...The Haunting looks like a great demo disc ... I need to buy it...
It is, but I think the dts version is out of print. You'll have to look into some place like Half.com or Amazon Marketplace for a used one. The good news it that it's cheap, usually < $10.

I want to say hi to everyone, this is my first post on this forum. I just completed a marathon of reading on the sub rankings. I started over on Audioholics, but that one ended for some reason. These are some pretty active threads over here. I usually lurk about on the Axiom forums and they move at a snails pace compared to these.

If craig or anyone can answer my question I would appreciate it. I have a SVS PB12+2 with the older shiny aluminum drivers. Is it worth $300.00 plus s/h to upgrade the drivers to the newer 12.3 versions? Although I am happy with the current drivers, I could use a little more punch in my room. It is 19' x 20' x 10' ceilings with an opening to the dining room, the kitchen and a stairwell in the back of the room. Although it sounds decent it could use a little more slam in my opinion. There is really not anywhere else to put another sub in my room. The sub is in it's fourth location and definitely sounds best where it is at now. I don't think adding another sub in the available locations would do much good, because the sub did'nt perform well in any of those locations. Upgrading might be a better alternative (financially) than selling it and getting a more powerful sub such as the new SVS Ultra that will be out soon, or the HSU HO, or ........If it will not make a noticeable improvement I will just leave it as is and replace it somewhere in the distant future.

I want to say hi to everyone, this is my first post on this forum. I just completed a marathon of reading on the sub rankings. I started over on Audioholics, but that one ended for some reason. These are some pretty active threads over here. I usually lurk about on the Axiom forums and they move at a snails pace compared to these.

If craig or anyone can answer my question I would appreciate it. I have a SVS PB12+2 with the older shiny aluminum drivers. Is it worth $300.00 plus s/h to upgrade the drivers to the newer 12.3 versions? Although I am happy with the current drivers, I could use a little more punch in my room. It is 19' x 20' x 10' ceilings with an opening to the dining room, the kitchen and a stairwell in the back of the room. Although it sounds decent it could use a little more slam in my opinion. There is really not anywhere else to put another sub in my room. The sub is in it's fourth location and definitely sounds best where it is at now. I don't think adding another sub in the available locations would do much good, because the sub did'nt perform well in any of those locations. Upgrading might be a better alternative (financially) than selling it and getting a more powerful sub such as the new SVS Ultra that will be out soon, or the HSU HO, or ........If it will not make a noticeable improvement I will just leave it as is and replace it somewhere in the distant future. Hello Atascocita,
I guess the first thing you may try is to remove all the port plugs (you may know this already).

Bass traps and/or a PEQ like the BFD ($100 - takes lots of work) or SMS-1 ($700?, very easy to use).

That will get you MUCH more performance out of your sub/setup than upgrading drivers.

I'd suggest asking SVS, biggsly5000. They're usually honest in their replies and will give you a good idea what to expect from the driver upgrade. As I understand it, it's mostly a gain of about 2-3dB maximum output.

Since "slam" is usually mid-bass, you might consider Hsu's MBM-12 for ~ $400 instead. Might be closer to giving you what you are looking for, assuming you have a good place for one (near your seating area).

Opps... OT again.

Macfan424----Good idea I had not even thought of that. It looks like I could stick the MBM-12 right on top of the SVS. What would really be cool is if SVS could produce a +2 or ultra2 with one driver for upper bass and one for lower frequencies as well.

Liaury and cyberbri -----I have read a few posts about how to equalize your sub for your room and looked at the graphs and when I finished I wondered what the hell I just read. They start talking about fundamentals, harmonics, octaves and I just tune out. I'm not really interested in getting into all of that, I'm not that concerned about it and sounds like a royal pain to me. Besides in the current location it sounds pretty good.

Thanks for all replies, need to think about this one awhile.

Liaury and cyberbri -----I have read a few posts about how to equalize your sub for your room and looked at the graphs and when I finished I wondered what the hell I just read. They start talking about fundamentals, harmonics, octaves and I just tune out. I'm not really interested in getting into all of that, I'm not that concerned about it and sounds like a royal pain to me. Besides in the current location it sounds pretty good.




If it sounds "pretty good," why are you looking to upgrade? If it's the room/location that's broken, upgrading would be throwing money away.

There is a lot of technical mumbo jumbo, but the basics of it are this:

Even with a subwoofer that technically plays "flat," when you put it inside a room, the room's dimensions, constructions, and objects in the room (and the location of the sub versus the location of the listening position) do weird things to the frequency response. The signal from 72Hz to 83Hz could have a 10dB peak (6~10dB "seems" like 2x the volume), while there could be a 15dB dip/null from 51~58Hz, totally sucking the energy out of any bass that happens to fall in that range.

You say you want more "punch." That punch is in the 50~80Hz range. You can "fix" it with something like the MBM, but before you even get that far, you should know what exactly you are "fixing." Perhaps due to the location of your seating position, you are sitting in a "null" where frequencies in that range are cancelling each other out, sucking out the "punchy" bass compared to the other frequencies. Or maybe you have a huge amount of gain (volume boost) in the lower frequencies, so it totally overpowers the higher frequencies.

If the problem is the room, and there's a good chance it is, upgrading drivers/sub isn't going to do a whole lot.

Assuming you have an SPL meter to calibrate your speakers and subwoofer, the next step would be to buy/borrow the Avia setup disc. It features a ton of things to help tweak your system, including "frequency sweeps" that start at one frequency and gradually go down to another frequency (mainly 200Hz to 20Hz). You play the sweeps and monitor the SPL meter to see how flat or bumpy your response is.

If you know the response is bumpy, you can start by experimenting with sub placement. Moving it even 6" or a foot along a wall, giving it 6" more clearance in the back, etc. can make a very noticeable difference. And you can even check to see if your couch puts you in a big null (where bass cancels out and volume drops significantly at that frequency), and possibly by moving the couch forward or backward 6-12" or whatever you could possibly get out of that null or at least make it not so drastic.

The BEST fix for bad room acoustics, after experimenting with placement, is bass traps, or panels or wedges of special thick absorption that absorb standing bass waves that cancel each other out or add together for big peaks. This smooths out the frequency response some (more if you add more), and has the added bonus of getting rid of a lot of ringing and boominess. You don't realize it's there, but when you add bass traps and hear the actual bass rather than the boominess and ringing created by the room, it's an amazing revelation.

The other way to directly control the frequency response you are getting is with an EQ. Something like the SMS-1 or RDES(?) gives you a microphone, the hardware, and an on-screen display so you can see readings in real-time and adjust filters/sliders to adjust the frequency response.

Getting the frequency response reasonably flat, so notes and sound effects in the bass region play at an equal volume relative to other notes, rather than overpowering or being over-shadowed by other notes, brings out the detail and texture and brings back the "slam" and "punch." Even just a few bass traps go a LONG way to cleaning up the bass and making it clearer and more detailed and textured, and then an eq on top of that takes it even further.

For example, here's my in-room response for my VTF-3 MK2, no eq but with bass traps (looks worse with no bass traps). Note that 74Hz is about 15dB louder (2~3x as loud) than the 50~60Hz range.

http://www.hometheatershack.com/forums/attachments/bfd-rew-forum/1841d1169541819-rew-rs-digital-meter-strange-results-high-freqs-20hz-filter-3_new-speaker-positions_raw_no-filters.jpg


Here's what I was able to do with an eq by cutting the level of several frequency ranges (and slightly boosting a few others):
http://www.hometheatershack.com/forums/attachments/bfd-rew-forum/1842d1169541819-rew-rs-digital-meter-strange-results-high-freqs-20hz-filter-3_new-speaker-positions.jpg


If you live in the bay area / silicon valley, you are welcome to drop by some weekend and hear before/after with bass traps and an eq. :D Knowing what I know now from first-hand experience, personally I'd rather spend $500 on a sub like the VTF-2 MK3 (very close to what I own - VTF-3 MK2) and buy bass traps and an eq, than buy a VTF-3 MK3 or even HO with no bass traps or eq.


PS - an "octave" is a doubling or halving of a frequency. So 20-40Hz is an octave, 40-80Hz, 80-160Hz, or 30-60, 60-120, 5000-10000, 5-10, 15-30, etc. And I believe fundamentals are for individual notes - like if you play a note on a bass guitar that centers around say 124Hz, there will be a fundamental at 62Hz that gives the note "body" or foundation, makes it sound fuller. If you can't hear that 62Hz funamental, the note sounds weak.

craig,

Have you been able to get the Orb Audio Super 8 for testing yet? Still interested to see how it stacks up. Especially since evryone who has one seems to love it. I still love mine, but this 3.3 is just crazy ggod.

craig,

Have you been able to get the Orb Audio Super 8 for testing yet? Still interested to see how it stacks up. Especially since evryone who has one seems to love it. I still love mine, but this 3.3 is just crazy ggod.

I have not even talked to the Orb people yet. It might help if I got off my butt and called them ... :D

THE HAUNTING DTS UPDATE....

OK mains, center and surrounds are all set perfectly at 75DB using my Pioneer 1014 internal test tone.

Then using the Internal Test tone I have the Sub set at 80db....I can work that to 81 if I want using the reciever....

Played the HAUNTING scene that we have been talking about......the chufffing has mostly gone away after recalibrating the sub, but it is still there a little (Because i'm listening for it...LOL)

SPL on the SPL meter was about 99-101db for that particular 22hz scene.....

What volume level under ref level are you listening at? Of course receiver tones give a different ref level than using Avia, but knowing if it's -5 or -20 will give a general idea. I have the DVD at home, lent from a friend (need to get it back to him soon), and I want to check out the scene again too. If for no other reason, at least to check my SPL. :D

I also have the particular scene on one of the AVS demo disks, and that scene is about all that DVD is good for...

Craigsub - An idea. Are you willing to send me subs whose objective measurements have been credibly questioned? If so I am happy to measure them and share what I discover and send them back. I can post video to YouTube or Google Video. This might be good for the community as well as fun.

An example could be the sub that you claim drops nearly all output at 45 Hz when the limiter hits. There are others...

I believe he pays for the subs out of his own pocket. You could do the same...

OH...should have noted that..........

I had the Reciever at -10db.....

the 75db speakers and 80db subwoofer settings were at -0db on the reciever....

Really anything past -10db on the reciever with a DTS soundtrack is just TOO DAMN LOUD!

Craigsub - An idea. Are you willing to send me subs whose objective measurements have been credibly questioned? If so I am happy to measure them and share what I discover and send them back. I can post video to YouTube or Google Video. This might be good for the community as well as fun.

An example could be the sub that you claim drops nearly all output at 45 Hz when the limiter hits. There are others...

Stan, You won't find where I "claim" anything. What you will find is 2 TrueRTA graphs of the Master & Commander scene on the PB12-NSD.

Here is one graph:

http://img.photobucket.com/albums/v171/craigsub/pb12mc.jpg

Here is another graph, same subwoofer, same scene, same location in room, same location for the microphone.

http://img.photobucket.com/albums/v171/craigsub/SVSPB12MCpartII.jpg

The only difference ? I stopped Increasing the SPL before hitting what is pretty clearly the max output of the unit. Note the slightly lower SPL @ 20 Hz (and close to 20 Hz) and the much higher SPL @ 45 Hz.

And Stan, as mentioned, I paid for all these products. Why would I send you something I paid for ? Do you think all your good natured comments, full disclosure, and reasonable demeanor is winning me over ? ;)

Craigsub - An idea. Are you willing to send me subs whose objective measurements have been credibly questioned? If so I am happy to measure them and share what I discover and send them back. I can post video to YouTube or Google Video. This might be good for the community as well as fun.

An example could be the sub that you claim drops nearly all output at 45 Hz when the limiter hits. There are others...



You are really starting to annoy me. I

Seriously........LEAVE CRAIG ALONE, LEAVE THIS THREAD ALONE, and better yet........LEAVE AVS ALONE.

He is doing great things for everyone....

Craig........do not waste your time posting to that jackass.......spend your time on something more important like your family, having a beer, testing subs......

EVERYONE...PLEASE IGNORE SJMARCY NO MATTER WHAT HE WRITES....GOOD OR BAD...WHO CARES!

Craigsub - An idea. Are you willing to send me subs whose objective measurements have been credibly questioned? If so I am happy to measure them and share what I discover and send them back. I can post video to YouTube or Google Video. This might be good for the community as well as fun.

An example could be the sub that you claim drops nearly all output at 45 Hz when the limiter hits. There are others...

Hi Stan,

I'm not sure if you remember me from when I was a younger know-it-all following all the DIY speaker happenings back in the day, but I do recall reading of your projects and some of Nousaines testing around that time or after. It's good to have another member back again who has real measurement and experimentation experience.

I think we might be overlooking something that goes back to the nature of posting graphs like Craig is.

If somone has been following along closely through Craig's adventures in bass, they would likey notice that the more recent comparison graphs are NOT frequency response measurements. It would probably save a bit of confusion if the labels of the graphs were something like "Max spectral output during X scene of Y length."

The fact that this is a peak hold display over an extended time at least opens the possibility that different limiter settings and release times could pull down subsequent, brief transients once the level is pushed hard into the limiter. The fact that the 45Hz level begins to come back when the playback level is lowered would align with this possibility. The amount of reduction does seem curiously high, and should be examined to be explained, but it isn't necessarily impossible.

THE HAUNTING DTS UPDATE....

OK mains, center and surrounds are all set perfectly at 75DB using my Pioneer 1014 internal test tone.

Then using the Internal Test tone I have the Sub set at 80db....I can work that to 81 if I want using the reciever....

Played the HAUNTING scene that we have been talking about......the chufffing has mostly gone away after recalibrating the sub, but it is still there a little (Because i'm listening for it...LOL)

SPL on the SPL meter was about 99-101db for that particular 22hz scene.....
bgillyjcu,
Thanks for posting the max SPL. I have mentioned this before several times in other threads and it is about using a sub-sonic filter. If you don't already have one, try one and set it to 20Hz and see if that gives you better performance.
This is a long thread so I am sorry if you have already posted this info. What is your room volume and is your sub corner loaded?
Thanks,
-Jai

Craigsub - An idea. Are you willing to send me subs whose objective measurements have been credibly questioned? If so I am happy to measure them and share what I discover and send them back. I can post video to YouTube or Google Video. This might be good for the community as well as fun.

An example could be the sub that you claim drops nearly all output at 45 Hz when the limiter hits. There are others...

Gentlemen. I think we should cut Sjmarcy some slack. I don't see anything disingenous in this comment and he is somewhat new to this forum and thread.

Rather than asking for Craig's subs I suggest you source your own, borrow them or buy them and post the results. One thing for sure Craig's measurments are consistent, but if you think there is a defective sub in the lot or something you disagree with then provide another measurement. It sounds like you have the tools so measure some sweeps and make a real contribution. Perhaps you have identified an abnormality but without presenting alternate data its difficult to listen to you cry wolf.

blah

Relax...please...such posts are counterproductive.

bgillyjcu,
Thanks for posting the max SPL. I have mentioned this before several times in other threads and it is about using a sub-sonic filter. If you don't already have one, try one and set it to 20Hz and see if that gives you better performance.
This is a long thread so I am sorry if you have already posted this info. What is your room volume and is your sub corner loaded?
Thanks,
-Jai


The sub is corner loaded indeed.

Living room iis 12x16x8.....that opens into a Dinning room that is 12x12x8 (There is really only about a 4 foot wall seperating the LR and DR.....otherwise I guess it could be considered "open"

The diining room has a door-width opening to the kitchen....

The sub is corner loaded indeed.

Living room iis 12x16x8.....that opens into a Dinning room that is 12x12x8 (There is really only about a 4 foot wall seperating the LR and DR.....otherwise I guess it could be considered "open"

The diining room has a door-width opening to the kitchen....
Thats about 2700 cu ft, not too large. I would try the subsonic filter and maybe time for an MBM-12 :D

If somone has been following along closely through Craig's adventures in bass, they would likey notice that the more recent comparison graphs are NOT frequency response measurements. It would probably save a bit of confusion if the labels of the graphs were something like "Max spectral output during X scene of Y length."

Alot of money spent.
Alot of work done.

.... no real measurements ? rofl .........

It would probably save a bit of confusion if the labels of the graphs were something like "Max spectral output during X scene of Y length."



This is interesting. How many times do I have to say this is a scene from Master and Commander before it sinks in ? There were several requests for graphs of movie scenes, especially considering the fact that we cannot take subwoofers out into a foot of snow for a GP session.

Thats about 2700 cu ft, not too large. I would try the subsonic filter and maybe time for an MBM-12 :D

The sub has a naturally built in subsonic filter........very steep roll off after 18hz...

The sub has a naturally built in subsonic filter........very steep roll off after 18hz...
Are you sure? I saw the plate pics and didn't find any switch there. Unless the amp is programmed that way or there are passive filters installed. You may want to check with Tom regarding this. Or maybe someone else here might know if the natural roll-off puts undue stress on the driver at the subsonics.
-Jai

If somone has been following along closely through Craig's adventures in bass, they would likey notice that the more recent comparison graphs are NOT frequency response measurements. It would probably save a bit of confusion if the labels of the graphs were something like "Max spectral output during X scene of Y length."

Alot of money spent.
Alot of work done.

.... no real measurements ? rofl .........

Laugh all you like, its indicative :rolleyes: . Anyone can see they are amplitude graphs of certain movie scenes and not FR based on sweeps. Its been mentioned at least half a dozen times. There is no confusion to anyone following this thread and, while more technically accurate, renaming the graphs doesn't change anything. What we do have is a question posed regarding one subwoofer's seemingly abnormal behaviour during part of a scene. Its something worth following up on and the right person to do it is the guy who posed the question.

When something like that has bothered me enough I've done the analysis and presented alternate data and I expect the same here from Stan otherwise his posts serve no purpose but to disrupt the flow of this thread.

Are you sure? I saw the plate pics and didn't find any switch there. Unless the amp is programmed that way or there are passive filters installed. You may want to check with Tom regarding this. Or maybe someone else here might know if the natural roll-off puts undue stress on the driver at the subsonics.
-Jai



Ed Mullen and I had email conversations about it.....but my work email is down. As soon as it is back up and running I'll post the conversation...

This is interesting. How many times do I have to say this is a scene from Master and Commander before it sinks in ? There were several requests for graphs of movie scenes, especially considering the fact that we cannot take subwoofers out into a foot of snow for a GP session.

*I* know what I'm looking at, but there have been repeated times that questions have suggested that others don't. At this point it's more clear, but if someone tries to catch up, they could certainly missunderstand. The point is that it's not a measurement that people are used to seeing and at first glance the measurements look like frequency responses. It's not a big deal to me how the graphs are labeled, I'm just making an observation of what I see happening, and more detail might save some confusion.

The nature of very lengthy and ongoing threads makes it cumbersome to find previous measurements quickly. In the interest of not making it a rediculously long explanation for every such measurement, a simple note of "Peak Hold results for ABC movie, 00:00-99:99" or something similar quickly makes the information pretty clear. While not telling us specific info, the length of time for the measurement does provide more info and understanding of the variables involved, and makes it something others can approximate on their own and compare relative differences between subs.

My last post was meant to help, not nitpick. It does look rather likely that the difference questioned recently is explained by the differences in limiting behavior over a longer interval of time, and is a behavior worth identifying and noting. The only other suggestion I have which I would find of interest is to note with the graphs what the audible or measured ques are that set the limit for each subwoofer and what sounds are or are not made showing distress. You had noted this on the PB12-NSD and it would be interesting to add that observation in future tests as well.

As a designer of limiter circuitry, I have been exposed to a topology that can have this described behavior. The system was termed a "moving high-pass filter". It consisted of a 2nd order high-pass Sallen & Key with a Q significantly higher than 1. This setting provided bass boost to compensate for driver/box rolloff. Key resistive components are replaced with modulated impedances to allow dynamic filter retuning with a control voltage derived from input signal level. If the limiter ratios were recursive, its possible to reduce boost at a rate slightly greater than the increase in signal, if combined with overall compression at the same time. If the bass response at 20Hz is strictly excursion limited, then it is CORRECTLY TUNED to prevent any further output at that frequency, but also lets 45Hz climb to levels 6dB higher, since that results in the same excursion. As I see in CraigSub's graphs energy below 20Hz, it may be another form of EQ that is dynamically changed. Conversely, I suppose the scene may have timing that is fighting against the decay period of the limiter circuitry

I basically abandoned all forms of limiters that work on the threshold/attack/decay format. Instead, I apply frequency selective soft clipping, which is a cycle-per-cycle approach. It introduces harmonic distortion only on the peaks that need it, and causes zero effect on all bass away from peaks. Then it removes the harmonics with additional filtering, leaving a fixed level sine wave behind regardless of increasing signal input. By doing this processing before the crossover lowpass filter, or as a multi-band array followed by aligned band-pass filters, its operation is imperceptible except as a lack of shotgun-in-the chest impact at the peaking frequencies. Any other limiter type causes a general bass level decrease for some time after a peak(often as long as a second), and that ruins the body of bass output for the sake of peak control.

Please consider a limiter as a SAFETY DEVICE. I believe all products should have an LED light up to indicate any limiter action like pro gear does. To be actually serious about bass performance, full desired playback volume should occur below any threshold of limiting, driver distress, or amplifier clipping. If any of these errors are occuring, buy more subs...

heheh

Laugh all you like, its indicative :rolleyes: . Anyone can see they are amplitude graphs of certain movie scenes and not FR based on sweeps. Its been mentioned at least half a dozen times. There is no confusion to anyone following this thread and, while more technically accurate, renaming the graphs doesn't change anything. What we do have is a question posed regarding one subwoofer's seemingly abnormal behaviour during part of a scene. Its something worth following up on and the right person to do it is the guy who posed the question.

When something like that has bothered me enough I've done the analysis and presented alternate data and I expect the same here from Stan otherwise his posts serve no purpose but to disrupt the flow of this thread.

Exactly right and well said John.

Okay, here is the first post where craigsub started posting the "peak hold" measurements for different subs - these scenes being from WotW. It's near the end of the page, and continues on subsequent pages. This is a good place to read more about what these graphs actually are all about.

http://av123forum.com/showthread.php?threadid=15586&perpage=15&pagenumber=60

If that link doesn't work, it's page 60 of this:
http://av123forum.com/showthread.php?threadid=15586

And remember, this is just one guy buying all these subs on his own, running tests in his spare time, calling friends over to do blind tests. All for the benefit of EVERYONE ELSE. Although I am sure he derives some sort of pleasure out of it, otherwise he wouldn't be doing it. I am grateful for all this and I am learning a lot, as I am sure others are as well. At the very least, it's interesting to follow.

So, thanks, craigsub. I hope you keep this up.

I don't know if I'll be able to do it in the scope you are, but I would love to have some friends over with their sub, run some sweeps and measurements, and compare subs. I have done it with some other great guys in the area, just listening to speakers and subs. But now I can run REW, etc.

As a designer of limiter circuitry, I have been exposed to a topology that can have this described behavior. The system was termed a "moving high-pass filter". It consisted of a 2nd order high-pass Sallen & Key with a Q significantly higher than 1. This setting provided bass boost to compensate for driver/box rolloff. Key resistive components are replaced with modulated impedances to allow dynamic filter retuning with a control voltage derived from input signal level. If the limiter ratios were recursive, its possible to reduce boost at a rate slightly greater than the increase in signal, if combined with overall compression at the same time. If the bass response at 20Hz is strictly excursion limited, then it is CORRECTLY TUNED to prevent any further output at that frequency, but also lets 45Hz climb to levels 6dB higher, since that results in the same excursion. As I see in CraigSub's graphs energy below 20Hz, it may be another form of EQ that is dynamically changed. Conversely, I suppose the scene may have timing that is fighting against the decay period of the limiter circuitry

I basically abandoned all forms of limiters that work on the threshold/attack/decay format. Instead, I apply frequency selective soft clipping, which is a cycle-per-cycle approach. It introduces harmonic distortion only on the peaks that need it, and causes zero effect on all bass away from peaks. Then it removes the harmonics with additional filtering, leaving a fixed level sine wave behind regardless of increasing signal input. By doing this processing before the crossover lowpass filter, or as a multi-band array followed by aligned band-pass filters, its operation is imperceptible except as a lack of shotgun-in-the chest impact at the peaking frequencies. Any other limiter type causes a general bass level decrease for some time after a peak(often as long as a second), and that ruins the body of bass output for the sake of peak control.

Please consider a limiter as a SAFETY DEVICE. I believe all products should have an LED light up to indicate any limiter action like pro gear does. To be actually serious about bass performance, full desired playback volume should occur below any threshold of limiting, driver distress, or amplifier clipping. If any of these errors are occuring, buy more subs...

heheh
Welcome! Who are you?
I had mentioned this a few times during phone conversations with audio equipment manufacturers, something similar to OBDII dignostics that are so common in modern day automobiles to register error codes. Strange analogy :) but makes sense. Viewing speakers like engines, it would be nice to have error codes stored in non-volatile memory. For me, this would have been invaluable if I had known if my sub was reaching limitations and some indicator of why. So yes, I am completely with you when you say all products should have at least an LED light indicating limiter actions.

About the moving high-pass filter, if I understand you right, what you are implying is that it moved to 45Hz due to dynamics at that point of time where the levels were measured? When pushed to limits, laws of physics obviously kick in and things start breaking loose (hooke's law, terminal velocity, nuclear effects etc etc).
I don't know what circuit is used in that sub, but if it is a loop like what you are referring to, I can see why this would happen. IMHO, there are too many variables in the real world where the measurments were done, predicting what could have happened is extremely hard.
-Jai

Thanks for that post LowOrder as it presents a credible explanation for the observed difference in amplitude instead of specualtion or innuendo regarding Craig's measurement. If true your explanation points to a significant design flaw of the limiter implentation in the PB12-NSD.

Thanks for that post LowOrder as it presents a credible explanation for the observed difference in amplitude instead of specualtion or innuendo regarding Craig's measurement. If true your explanation points to a significant design flaw of the limiter implentation in the PB12-NSD.

John ... Based on the experience with the PB12 ... I think the limiter does a great job. I mentioned this earlier, but thought re-stating this would be important. I REALLY pushed the PB12 to see how hard it could hit @ 20 Hz ... had I tried this with the VTF-2.3, I probably would have destroyed the driver.

The protection circuitry in the PB12 makes it totally ... for lack of a better term, "idiot proof". When you think about a relatively entry level sub ... bullet proof makes sense.

That being said ... kudos for following Loworder's post. It was extremely well written. And very ... smart ...

Thanks for that post LowOrder as it presents a credible explanation for the observed difference in amplitude instead of specualtion or innuendo regarding Craig's measurement. If true your explanation points to a significant design flaw of the limiter implentation in the PB12-NSD.
Jakeman,
I got slapped over and over again for mentioning the word "design flaw" last time :eek: so watch out. I hope the forum will turn into a place where people can freely express what their opinions are without the fear of being flamed. I welcome your opinion. I only hope people won't get rude. I now have tuned myself not to take things personally. Challenging the status quo is a good virtue and I hope more people will accept it. While I openly acknowledge I am "fan" of SVS, your comments still don't bother me.
Take care,
-Jai

John ... Based on the experience with the PB12 ... I think the limiter does a great job. I mentioned this earlier, but thought re-stating this would be important. I REALLY pushed the PB12 to see how hard it could hit @ 20 Hz ... had I tried this with the VTF-2.3, I probably would have destroyed the driver.

The protection circuitry in the PB12 makes it totally ... for lack of a better term, "idiot proof".

That being said ... kudos for following Loworder's post. It was extremely well written. And very ... smart ...
Couldn't agree more. Loworder, can you disclose who you are? Just curious, you sure are not a casual audio guy. I had to read your post 2 times before I understood what you said and there is logic behind it which I appreciate.
Craigsub,
Is the protection circuitry in the NSD the same as the PB12. While I don't completely buy your ratings (from your posts, I think you will respect my opinions), I do have a high degree of respect for you and what you contribute to this forum. Keep it up!
-Jai

Couldn't agree more. Loworder, can you disclose who you are? Just curious, you sure are not a casual audio guy. I had to read your post 2 times before I understood what you said and there is logic behind it which I appreciate.
Craigsub,
Is the protection circuitry in the NSD the same as the PB12. While I don't completely buy your ratings (from your posts, I think you will respect my opinions), I do have a high degree of respect for you and what you contribute to this forum. Keep it up!
-Jai

When you ask "Is the protection circuitry in the NSD the same as the PB12?" ... Do you mean the PB12-NSD vs. the PB12-Plus/2 ? If so ... I don't know if they are the same.

As for the ratings ... I am sure that, if we took 20 guys from here, we would get 20 different ratings for the subs ... ESPECIALLY using blind tests. I think there would be some consistency ... but also some variances in the point totals.

craigsub,

You mentioned that at least for some of the test that led to the # ratings, you had some musician friends, etc. over, correct? Are the #scores and rankings based on the general consensus from the sessions? Or was that just part of it. I know you've been doing a lot of this over the last 3~ months or so.

craigsub,

You mentioned that at least for some of the test that led to the # ratings, you had some musician friends, etc. over, correct? Are the #scores and rankings based on the general consensus from the sessions? Or was that just part of it. I know you've been doing a lot of this over the last 3~ months or so.

Yes ... Some musicians .. my brother's lead engineer .. there are always several opinions in regards to the SQ of each sub.

When you ask "Is the protection circuitry in the NSD the same as the PB12?" ... Do you mean the PB12-NSD vs. the PB12-Plus/2 ? If so ... I don't know if they are the same.

Yes, I meant the PB12-NSD vs the Plus/2.
That's ok. Maybe Tom or Ron will chip in.
Thanks,
-Jai

You are really starting to annoy me. I Seriously........LEAVE CRAIG ALONE, LEAVE THIS THREAD ALONE, and better yet........LEAVE AVS ALONE.
He is doing great things for everyone....Craig........do not waste your time posting to that jackass.......spend your time on something more important like your family, having a beer, testing subs......EVERYONE...PLEASE IGNORE SJMARCY NO MATTER WHAT HE WRITES....GOOD OR BAD...WHO CARES!

This seems like a possible violation of forum policy.

I read your post, and am saddened. Free speech and a sharing attitude can be good in a forum. For some reason I am reminded of Google cofounder Brin's recent comments about censorship. He now feels there censorship was not a good idea. Here is an interesting article about it should you want to know more:

http://business.guardian.co.uk/davos2007/story/0,,1999994,00.html

Reviewer Craigsub most assuredly did make 14.5-18.5 dB claims, others did note they understood this fact, and used it to justify their positions and thanked him. Obviously there is misinterpretation here, and I have certainly been hassled about the matter. Craigsub retested the device and reconfirmed his results. I have not checked to see if those posts are still here and in unedited form. Perhaps a disclaimer on these tests is needed so that matters are clearer to more members. Things like this, but not just this concern me in this murky series of tests and ratings which members use to evaluate their options.

I believe he pays for the subs out of his own pocket. You could do the same...

Sure I could do that. But if a reviewer claims a sub suddenly cuts it's output so massively when 3 more dB of input are added then this begs the question is the sub broken or not, design issue or not, do they all do this, etc. If it is broken then how can that be ascertained if I buy and test a different subwoofer? It seems to me that it would make more sense to test the one whose behavior was so greatly different than other tested devices. I am concerned when asking such things leads to efforts to ban someone like me, and a series of attacks across various forums besides this one. It sends the message that noone can discuss this matter and that hand claps are the only suitable responce. So in effect a sub that ran into a design issue, or broke, or a test issue seems to have uncovered a larger issue here. The fact that these tests/ratings cannot be discussed in an open manner without a person risking attacks. I received many PMs and emails about this matter confirming these concerns. For example if a reviewer finds himself banned at other forums (such as Craigsub) after testing a sub from a certain manufacturer...and then runs into various "issues" with subs from that manufacturer it presents concerns about conflicts of interest and motivations that harm credibility.

Gentlemen. I think we should cut Sjmarcy some slack. I don't see anything disingenous in this comment and he is somewhat new to this forum and thread. Rather than asking for Craig's subs I suggest you source your own, borrow them or buy them and post the results. One thing for sure Craig's measurments are consistent, but if you think there is a defective sub in the lot or something you disagree with then provide another measurement. It sounds like you have the tools so measure some sweeps and make a real contribution. Perhaps you have identified an abnormality but without presenting alternate data its difficult to listen to you cry wolf.

Normally when such an unusual test result is found, the reviewer would look into the manner on their own. Since it is not normal, or desireable behavior. I noticed that when these reviews or tests are discussed, it is common for the person in my position to get attacked. It would be nice if that did not occur as it tends to eliminate the topic being discussed. Instead, a shoot the messenger tone develops which is not good for the credibility of these tests or this forum and it's members.

Jakeman,
I got slapped over and over again for mentioning the word "design flaw" last time :eek: so watch out. I hope the forum will turn into a place where people can freely express what their opinions are without the fear of being flamed. I welcome your opinion. I only hope people won't get rude. I now have tuned myself not to take things personally. Challenging the status quo is a good virtue and I hope more people will accept it. While I openly acknowledge I am "fan" of SVS, your comments still don't bother me.
Take care,
-Jai

Well said. If things like "howcum this happened?" are discussable then I think it is better for all concerned. If a sub suddenly nearly turns off in normal use this is not a good thing but is what this sub seems to have done if Craig's tests are accurate here. I'd like to find out without having to be attacked. I have seen the very unclear test methodology glossed over, and mentioned that the sub could be broken or of a crummy design. Moderators got involved. Lets find out what happened here instead of claiming that I did something or that some company has me posting here which is a pointed personal attack, etc.

As a designer of limiter circuitry, I have been exposed to a topology that can have this described behavior. The system was termed a "moving high-pass filter". It consisted of a 2nd order high-pass Sallen & Key with a Q significantly higher than 1. This setting provided bass boost to compensate for driver/box rolloff. Key resistive components are replaced with modulated impedances to allow dynamic filter retuning with a control voltage derived from input signal level. If the limiter ratios were recursive, its possible to reduce boost at a rate slightly greater than the increase in signal, if combined with overall compression at the same time. If the bass response at 20Hz is strictly excursion limited, then it is CORRECTLY TUNED to prevent any further output at that frequency, but also lets 45Hz climb to levels 6dB higher, since that results in the same excursion. As I see in CraigSub's graphs energy below 20Hz, it may be another form of EQ that is dynamically changed. Conversely, I suppose the scene may have timing that is fighting against the decay period of the limiter circuitry
I basically abandoned all forms of limiters that work on the threshold/attack/decay format. Instead, I apply frequency selective soft clipping, which is a cycle-per-cycle approach. It introduces harmonic distortion only on the peaks that need it, and causes zero effect on all bass away from peaks. Then it removes the harmonics with additional filtering, leaving a fixed level sine wave behind regardless of increasing signal input. By doing this processing before the crossover lowpass filter, or as a multi-band array followed by aligned band-pass filters, its operation is imperceptible except as a lack of shotgun-in-the chest impact at the peaking frequencies. Any other limiter type causes a general bass level decrease for some time after a peak(often as long as a second), and that ruins the body of bass output for the sake of peak control. Please consider a limiter as a SAFETY DEVICE. I believe all products should have an LED light up to indicate any limiter action like pro gear does. To be actually serious about bass performance, full desired playback volume should occur below any threshold of limiting, driver distress, or amplifier clipping. If any of these errors are occuring, buy more subs... heheh

First of all, welcome. Second of all if this is occurring here...it would be great to find out.

craigsub, You mentioned that at least for some of the test that led to the # ratings, you had some musician friends, etc. over, correct? Are the #scores and rankings based on the general consensus from the sessions? Or was that just part of it. I know you've been doing a lot of this over the last 3~ months or so.

It warms my heart to see that this sort of thing is coming up, and hopefully without an attack on you. I have asked for more information, the blind test data, test methodology and was either ignored or attacked for the most part.

Can the test methodology and blind test procedures be disclosed in a clear manner and made available to interested readers? I have asked repeatedly. I think it would help clarify things.

I am sure that, if we took 20 guys from here, we would get 20 different ratings for the subs ... ESPECIALLY using blind tests. I think there would be some consistency ... but also some variances in the point totals.

I don't agree. I have been in blind tests, designed them, run them. When done right, the results are not a free for all at all.

Okay, here is the first post where craigsub started posting the "peak hold" measurements for different subs - these scenes being from WotW. It's near the end of the page, and continues on subsequent pages. This is a good place to read more about what these graphs actually are all about.

http://av123forum.com/showthread.php?threadid=15586&perpage=15&pagenumber=60

If that link doesn't work, it's page 60 of this:
http://av123forum.com/showthread.php?threadid=15586

And remember, this is just one guy buying all these subs on his own, running tests in his spare time, calling friends over to do blind tests. All for the benefit of EVERYONE ELSE. Although I am sure he derives some sort of pleasure out of it, otherwise he wouldn't be doing it. I am grateful for all this and I am learning a lot, as I am sure others are as well. At the very least, it's interesting to follow.

So, thanks, craigsub. I hope you keep this up.

I don't know if I'll be able to do it in the scope you are, but I would love to have some friends over with their sub, run some sweeps and measurements, and compare subs. I have done it with some other great guys in the area, just listening to speakers and subs. But now I can run REW, etc.
New27

Could you edit the first post in this thread to include these links?

This would help everybody, especially those joining late, to understand what Craigsub is doing.

This seems like a possible violation of forum policy.

I read your post, and am saddened. Free speech and a sharing attitude can be good in a forum. For some reason I am reminded of Google cofounder Brin's recent comments about censorship. He now feels there censorship was not a good idea. Here is an interesting article about it should you want to know more:

http://business.guardian.co.uk/davos2007/story/0,,1999994,00.html

Reviewer Craigsub most assuredly did make 14.5-18.5 dB claims, others did note they understood this fact, and used it to justify their positions and thanked him. Obviously there is misinterpretation here, and I have certainly been hassled about the matter. Craigsub retested the device and reconfirmed his results. I have not checked to see if those posts are still here and in unedited form. Perhaps a disclaimer on these tests is needed so that matters are clearer to more members. Things like this, but not just this concern me in this murky series of tests and ratings which members use to evaluate their options.


Mr. Marcy, please point out where I made the proclamation that the Hsu would out deliver the SVS @ 45 Hz.

If you can find this statement, it would be helpful.

I don't agree. I have been in blind tests, designed them, run them. When done right, the results are not a free for all at all.

You are one of thse guys who just cannot help himself. I never said anything about a free for all.

I don't agree. I have been in blind tests, designed them, run
them. When done right, the results are not a free for all at all.

You would still get some variation in scores since to me these are based on subjective experiences. It is like like me tasting a wine yesterday that was given a Wine Spectator score of 90, but I didn't care for the wine at all.

I supposed if people were trained in how to score their subjective impressions, perhaps the variation in scores would decrease, but you still see variation between these scores.

With that said, Craig did some blind listening tests between the EP500 and Ultra a year ago. Though variable, the 4-5 reviewers' scores were reasonably close to each other.

FWIW, I wouldn't call his listening tests a "free for all".

Well said. If things like "howcum this happened?" .


How Old are you???? Who in their adult mind would spell the words how come as howcum.

There is no way that an intelligent ADULT can misspell the word COME for CUM....

I'm seriously doubting any thread of intelligence on your end, rather, just the need to spark doubt on things and stir up problems.

If you don't like my posts....then please leave! :D

The PB12-NSD amp has a fixed high pass filter at ~18 Hz. It also has peak limiters which have adjustable parameters for attack/sustain duration and continuous/peak power levels. Craig is correct - the high pass and the limiters in this model have been designed to make the subwoofer just about bullet-proof, even when deliberately over-driven.

Regarding the 22 Hz "the cold" scene in The Haunting DTS, 100-101 dB on the RS meter at the listening position is about 106 dB actual sound pressure. This meter is equipped with a C-weighted filter which causes it to read low in the deep bass ranges. The C-weighted correction factor at 22 Hz is about 5 dB.

Also, running the subwoofer 5 dB hot on the RS meter (75 dB speakers, 80 dB sub) actually means the sub is running about 7 dB hot. While the spectral content of subwoofer calibration tones certainly varies with the AVR/source, they are generally centered in the 40-50 Hz region. So the RS meter reads about 1.5-2.0 dB low on the typical subwoofer test tone.

Running the subwoofer 6-7 dB hot is fine (everyone has different tastes in bass), but realize that a doubling of the subwoofer results in the 6 dB increase in headroom. So you're definitely a candidate for duals. :)

The closer the user pushes to Dolby Reference Level, the more we recommend running the subwoofer calibrated "flat" (i.e., even with the speakers) to prevent subwoofer overload and/or audible artifacts like port chuffing. That means about 73-74 dB on the RS meter if the speakers are calibrated to 75 dB.

Normally when such an unusual test result is found, the reviewer would look into the manner on their own. Since it is not normal, or desireable behavior. I noticed that when these reviews or tests are discussed, it is common for the person in my position to get attacked. It would be nice if that did not occur as it tends to eliminate the topic being discussed. Instead, a shoot the messenger tone develops which is not good for the credibility of these tests or this forum and it's members.

I've been in similar positions and attribute it to the sometimes rough and tumble culture at this forum. People get over it soon enough and move on to the next discussion thread though some egos do get bruised easily. I appreciate you don't have a recent history here and your early posts clearly showed a good knowledge of the subject matter but the tone of your statements invited the attacks. Yes a new poster with a critical message sometimes gets shot, so you have to have good reasons and a defensible position when waving a red flag. Just crying wolf doesn't cut it here. Speaking for myself its now history and no big deal and I welcome your comments. However the bar is higher at this forum than what you are suggesting.

Yes the reviewer should double check an unusual test result, which Craig did, but the onus is also on the poster to produce other data or evidence if you continue to be dissatisfied. Indirectly your persistence may have prompted that excellent post by LowOrder which has linked the suspicious results to an overaggressive limiter. :cool: Under these circumstances, if you are still not satisfied get the SVS sub and test it yourself especially its limiter.

In that regard I agree that Craig's testing comparisons would not make it in a scientific journal however no one here expects that standard. More importantly, the man is honest and experienced with many subs which is worth much more to many people here including myself. Please keep that in mind as you comment on any other problems and the guns will be put back in the rack. ;)

The PB12-NSD amp has a fixed high pass filter at ~18 Hz. It also has peak limiters which have adjustable parameters for attack/sustain duration and continuous/peak power levels. Craig is correct - the high pass and the limiters in this model have been designed to make the subwoofer just about bullet-proof, even when deliberately over-driven.

Regarding the 22 Hz "the cold" scene in The Haunting DTS, 100-101 dB on the RS meter at the listening position is about 106 dB actual sound pressure. This meter is equipped with a C-weighted filter which causes it to read low in the deep bass ranges. The C-weighted correction factor at 22 Hz is about 5 dB.

Also, running the subwoofer 5 dB hot on the RS meter (75 dB speakers, 80 dB sub) actually means the sub is running about 7 dB hot. While the spectral content of subwoofer calibration tones certainly varies with the AVR/source, they are generally centered in the 40-50 Hz region. So the RS meter reads about 1.5-2.0 dB low on the typical subwoofer test tone.

Running the subwoofer 6-7 dB hot is fine (everyone has different tastes in bass), but realize that a doubling of the subwoofer results in the 6 dB increase in headroom. So you're definitely a candidate for duals. :)

The closer the user pushes to Dolby Reference Level, the more we recommend running the subwoofer calibrated "flat" (i.e., even with the speakers) to prevent subwoofer overload and/or audible artifacts like port chuffing. That means about 73-74 dB on the RS meter if the speakers are calibrated to 75 dB.


Ed you are so knowledgeable! Knowing this I'll back the sub off about 3db. I obviously want to maximize performance across the Frequency range... Thanks :)

Nice post Ed!

Thanks for pointing out that the RS meter needs a compensation curve overlayed on its results, especially for the lowest accepted octave 20Hz - 40Hz. When developing products, I perform near-field testing using LMS, under 1" from the cone, excursion allowing. This is followed up with the THX-mandated 2meter ground-plane measurement, with the mic on the concrete floor facing the sub, in an open-plan manufacturing facility. The walls are all over 50ft away! Even so, care is given to locate the station away from dead center. As this isn't likely available to in situ home reviewers, more insight is now available regarding RS results.

I have access to the Phonic PAA3 and recommend it as a step-up from the basic functionality of the RS meter. One feature I like is the jog shuttle that lets you highlight a specific frequency for a digital decibel display. There are several response times to choose from, so RTA and average measurements can easily be obtained.

No I don't work for Phonic, although a company I contract for sells them. I do think its a more powerful and flexible tool as a logical next increment in testing gear.

:)

:( Thanks for that post LowOrder as it presents a credible explanation for the observed difference in amplitude instead of specualtion or innuendo regarding Craig's measurement. If true your explanation points to a significant design flaw of the limiter implentation in the PB12-NSD.

I suggest caution in concluding that any one type of limiter execution is a design flaw. At best they are design choices akin to how big a power amp and how large an enclosure can be used in a given design. Even more interesting is that one of Craig's favorite subs used sliding high pass limiting. Different limiter implementations have different effects depending on the particular system and what they are protecting the system from doing.

I see nothing *wrong* in the behavior observed and questioned in the PB12-NSD. The observation is very much as Craig noted, where the other subs hit some wall before a limiter can get aggressive enough to compress peaks like this. The PB12-NSD was bullet-proof enough to allow Craig to keep pushing to see what was possible down low. Bullet-proof or not, as Ed and others imply, this isn't a region of operation you want be observing often.

While it adds to the measurements taken quite a bit, the peak hold graphs would likely give us much more insight if 3 more measurements were added to the set. Ideally seeing a measurement with the level -5, -10, and -20 from maximum would give much more insight as to the behavior of the subwoofers, and give us a insight on the limiting behavior. Of course doing so multiplies the testing required by a factor of 4! :(

I suggest caution in concluding that any one type of limiter execution is a design flaw. At best they are design choices akin to how big a power amp and how large an enclosure can be used in a given design. Even more interesting is that one of Craig's favorite subs used sliding high pass limiting. Different limiter implementations have different effects depending on the particular system and what they are protecting the system from doing.

I see nothing *wrong* in the behavior observed and questioned in the PB12-NSD.
I second Mark's quote here. A design choice is not a design flaw.
I call something a design flaw when it does not deliver what it was intended and designed for. When operating within spec, if the product does not deliver as claimed and if there was no manufacturing defect, then in my mind, it is ok to call it a design flaw. I had reason to believe that I was operating within spec and to my knowledge there was no defect and I tried to address every possible area of potential defect but I had limited visibility and access into the product unlike the manufacturer who has full visibility. So now it is going back to the designer's hands.
Also, about titling the chart as Mark suggested is not a bad idea at all. It is a constructive comment which if taken and followed through will avoid confusion. I knew exactly what the charts were the first time I looked at them, but there are few who do get confused. Name your charts, name the axis with the correct names. Remove things which cause confusion. Simple guidelines which if easy to do in the software should be done.
As I indicated earlier, just by looking at these charts coming to conclusions is not right in my opinion. We need more data or tests if possible.
-Jai

I'm seriously doubting any thread of intelligence on your end, rather, just the need to spark doubt on things and stir up problems.

IMHO, I welcome any counterpoint. Without knowing the limitations of any experiment or study, it is difficult to assess the validity of any conclusions. What I have problems with is the tone that some people take when they make criticisms; it almost always seems to take a personal tone at this forum. :( What people don't seem to realize is that is that Craig takes his own time and money to these tests. Though he spends a lot of time on these tests, this is not his full time job (plus he has a family). We can scream until we're blue in the face of how he should change he can make his subwoofer tests "better", but it gets to the point where these changes are not feasible.

No study is perfect. Every study has limitations. But I think it would be ignorant to ingore any conclusions completely because a study has limitations. There is always something to take away. I think Craig said it best one of his previous posts, his listening tests are not meant to be the bible, but a guide. This is a guide that no one else has attempted to create. His tests have value.

How Old are you???? Who in their adult mind would spell the words how come as howcum.

There is no way that an intelligent ADULT can misspell the word COME for CUM....

I've been known to misspell words and make grammatical errors when I write my papers... So bad, that I have pressed the edit button 4 times to write this post. :) Though I'm not the brightest bulb in the shed, I don't think it is a fair indication of my intelligence. ;)

How Old are you???? Who in their adult mind would spell the words how come as howcum.

There is no way that an intelligent ADULT can misspell the word COME for CUM....

I'm seriously doubting any thread of intelligence on your end, rather, just the need to spark doubt on things and stir up problems.

If you don't like my posts....then please leave! :D
Let's not start this again.

Either add him to your ignore list, or just ignore him.

Don't take personal shots - we'll all lose. :(

I've been known to misspell words and make grammatical errors when I write my papers... So bad, that I have pressed the edit button 4 times to write this post. :) Though I'm not the brightest bulb in the shed, I don't think it is a fair indication of my intelligence. ;)



Seriously....i can see a misspelling, but CUM for COME? How could one POSSIBLY make that mistake by mistake! LOL

Seriously....i can see a misspelling, but CUM for COME? How could one POSSIBLY make that mistake by mistake! LOL
Actually, sjmarcy is no spring chicken. Nor am I. Back in the day (ours) "howcum" was common in the vernacular. It wasn't misspelling, per se, it was just informal usage. It probably never occurred to him that "cum" has acquired a meaning in current usage by younger people that it never had back then.

Sure I could do that. But if a reviewer claims a sub suddenly cuts it's output so massively when 3 more dB of input are added then this begs the question is the sub broken or not, design issue or not, do they all do this, etc. If it is broken then how can that be ascertained if I buy and test a different subwoofer? It seems to me that it would make more sense to test the one whose behavior was so greatly different than other tested devices. I am concerned when asking such things leads to efforts to ban someone like me, and a series of attacks across various forums besides this one. It sends the message that noone can discuss this matter and that hand claps are the only suitable responce. So in effect a sub that ran into a design issue, or broke, or a test issue seems to have uncovered a larger issue here. The fact that these tests/ratings cannot be discussed in an open manner without a person risking attacks. I received many PMs and emails about this matter confirming these concerns. For example if a reviewer finds himself banned at other forums (such as Craigsub) after testing a sub from a certain manufacturer...and then runs into various "issues" with subs from that manufacturer it presents concerns about conflicts of interest and motivations that harm credibility.


What makes YOU so special he should send HIS OWN sub to you? If that was your concern, why not advise him to contact SVS and see about getting a replacement?

And conversely, being banned at a certain forum for test results of a certain manufacturer's product could ALSO indicate that the manufacturer in question was not happy with the results and put pressure on the owners of the forum in question. Websites and forums run on advertising dollars...

Reviewer Craigsub

Perhaps a disclaimer on these tests is needed so that matters are clearer to more members. Things like this, but not just this concern me in this murky series of tests and ratings which members use to evaluate their options.

Here we go again ...... now your just making up condescending BS ..... since when has Craigsub ever stated he is "a reviewer"? Like all true audio enthusiasts he is just giving his "opinions" on what he has found. People would be absolutely foolish to rush out and buy (or discount) based on "one mans opinion".

If you are so concerned about Craig's tests and reports why don't you purchase all the same subwoofers he has ..... and then you can report your own opinion. That would earn you far more respect than just trying to discredit someone who is just giving his opinion (after spending considerable personal time and money)

Audio reproduction is just like our individual taste in food "it varies" and unless your just an SPL Junkie there is "NO Ultimate Numerical Buyers Guide" to finding the best subwoofer for you (regardless of all the theory). Listening and directly comparing your contenders is the only way to be 100% positive that you will make the right choice for you.

Ddavidson

Seriously....i can see a misspelling, but CUM for COME? How could one POSSIBLY make that mistake by mistake! LOL

When I read thewords howcum it didn't even occur to me that some would think it was a mistake. Have used howcum as slang for over 60 years. When I read your comment I googled howcum and found 40 pages of topics where someone had used that word (granted not all of them would be used in polite company). I hope we can get back to reading about subs. Thanks everyone for the great education. Howcum it took me so long to find this site?

Best
Ray

Does anyone else find the humor in this: A bunch of guys talking about subwoofers, and the conversation turning to the word "cum" ????

Howcum did that happen ? :eek: :confused: :D

Seriously....i can see a misspelling, but CUM for COME? How could one POSSIBLY make that mistake by mistake! LOL

I'm about ready to start ignoring you at this point.

Does anyone else find the humor in this: A bunch of guys talking about subwoofers, and the conversation turning to the word "cum" ????

Howcum did that happen ? :eek: :confused: :D
Craig, you've been running too many tests. Time for a break and a beverage.

Craig, you've been running too many tests. Time for a break and a beverage.

Agreed ... Tonight it will be a movie, some 40 year old burboun, and did I mention burboun ?

mmmmmm.... bourbon.

How many of you here have a PhD or ThD? :rolleyes:
I mean "Permanent Head Damage" or "Temporary Head Damage"?
I have a ThD because I come here every so often not always, especially when I have upgraditis :D. It is nice and sunny outside and I am reading these forums, especially this thread and the vernacular, on a nice Saturday morning and that is a sign of ThD. Get out of your seats gentlemen. Go out and have some fun or go enjoy your system! Let's all relax :cool:
I am outta here!

GUYS! PLS STOP THE AGGRESSIONS!!! SJMARCY DID NOT MEAN ANYTHING RELATED TO THAT "CUM", BUT THIS IS ONLY A "SPOKEN-WRITTEN" LANGUAGE, AND THIS "HOWCUM" EXPRESSION CAN BE FOUND IN MANY FORUMS.....

SJMARCY seems to be a knowledgeable guy, but has maybe jumped into this thread with quite direct, non-diplomatic quotes (IMO) in an aggressive fashion. Many of you have expressed refusal for his attitude.... OK! I think your messages were well received, But if SJMARCY has any questions/queries like this HOWCUM, why not take it seriously.... this may lead to answers which would help us all understand things from Guys who may have answers....

TO SJMARCY:

Craigsub is a GREAT guy, and also a knowledgeable guy, doing effort, spending money and time, for that has to be respected (indeed he has never claimed to be a Sub reviewer, but all of us are just discussing and exchanging opinions and experience). I think that it is not your questions which are upsetting guys here, but maybe the way they are asked.... I think "smoothing", and "reducing the tone" your post could lead to a better and constructive involvement in this thread....

I'm about ready to start ignoring you at this point.

You are right, I'm sorry...

BACK TO SUBWOOFERS for GOOD

I really wish a moderator would come in here and delete 90% of the posts in this thread, it has gotten so off topic that it's ridiculous and is becoming yet another thread where one has to sift through now some 825 posts to find the 40 or 50 really good, really useful ones.

I really wish a moderator would come in here and delete 90% of the posts in this thread, it has gotten so off topic that it's ridiculous and is becoming yet another thread where one has to sift through now some 825 posts to find the 40 or 50 really good, really useful ones.

Agreed! If you are not interested in this thread or do not agree with Craig's rankings, opinions, measurements, techniques, comments, etc. etc. why are you posting?

I agree. this bickering is pointless and annoying to sort through. please everyone realize that this is craigsub's opinion/graphs. if you do or dont agree thats fine, i dont think he cares. after all the title of this thread is "Official Craigsub rankings thread" not the "Everyone bicker about how they think craig should test HIS stuff" thread. i have read this entire thread and have yet to read a post from craig saying that this is the only correct way to test a sub. everyone relax

I really wish a moderator would come in here and delete 90% of the posts in this thread, it has gotten so off topic that it's ridiculous and is becoming yet another thread where one has to sift through now some 825 posts to find the 40 or 50 really good, really useful ones.amen

John ... Based on the experience with the PB12 ... I think the limiter does a great job. I mentioned this earlier, but thought re-stating this would be important. I REALLY pushed the PB12 to see how hard it could hit @ 20 Hz ... had I tried this with the VTF-2.3, I probably would have destroyed the driver.

The protection circuitry in the PB12 makes it totally ... for lack of a better term, "idiot proof". When you think about a relatively entry level sub ... bullet proof makes sense.

That being said ... kudos for following Loworder's post. It was extremely well written. And very ... smart ...


So the VTF2.3 has no protection so to speak? You could turn it up to much and heart the driver? Interesting, I would think that all subs would have some kind of circuit to protect the driver.

Craig and everyone,
As much fun as this has been, can we now move on. Time to pick a couple other subs to measure. No HSU, no SVS. Please start a new thread and let this one die an undignified death. How about a high end comparo between a Bose Acoustimass and a Dayton 10" kit. That ought to get some juices flowing. :)

So the VTF2.3 has no protection so to speak? You could turn it up to much and heart the driver? Interesting, I would think that all subs would have some kind of circuit to protect the driver.

The VTF-2.3 has very good protection. However, one must still exercise some restraint with it, or damage can occur.

I am going to be rather blunt here, and not ameliorate the following with humor.

Many people have noted that I don't get paid to do this. They are right. I have been offered "jobs" to review audio components. Each of these jobs has been turned down. I have no interest in someone paying me. That entitles that person to tell me what I can and cannot say.

I don't care who wins or loses these comparisons. In fact, I don't even view it as a win or lose. Let's look at the JL Audio Fathom 113. I have mentioned in many past thread that I might eventually enter the audio world professionally. By definition, professional means one gets paid. JL works strictly through a small body of exclusive dealers, and there is no chance that they would work in any sales model with which I would be involved.

That is irrelevant to the performance of their subwoofers. They make a fantastic subwoofer, and do so for a reasonable price. If I ever see the right opportunity to enter the field, it would not change my opinion of the JL product line.

I have the priviledge of having some fantastic products here for review, with more on tap for future review. For the most part, it is enjoyable.

To those who enjoy this process, and respond in a positive manner, thank you.

To those who post unwarranted attacks, please, do everyone a favor, and start a separate thread. When you open this thread, be specific in your complaint. Tell everyone using facts what the problem is. From that point, we can move forward.

Thanks for indulging me.

To those who enjoy this process, and respond in a positive manner, thank you.
What about those that are just freaking jealous...like me? :)

What about those that are just freaking jealous...like me? :)

We send you on a drinking trip with Kipp Jones, of course. :eek:

25 years ago I did an equalized reflex system with my Altec Voice of the Theater dual 15 inch woofers in 10 cubic foot boxes and had measurable output to 8 hz (which you can "hear" at least I can "hear") Driven with a meager 90 watt SAE receiver I never did crank them all the way up as the 16 foot window wall in the room seemed in jeopardy. Of course those drivers were rated 106 dB one watt one meter, each.

I would love to hear some of these newer wonder boxes.

The VTF-2.3 has very good protection. However, one must still exercise some restraint with it, or damage can occur.




what is meant by "pretty good protection?" does it have the same filter the pb-12 does or something else?

what is meant by "pretty good protection?" does it have the same filter the pb-12 does or something else?

By "pretty good" protection, it means that you have to almost TRY to damage the VTF-2.3 in order to cause harm. As long as someone uses common sense, the VTF-2.3 will be a great product. But, if you are abusive, you can damage the driver.

Are you sure? I saw the plate pics and didn't find any switch there. Unless the amp is programmed that way or there are passive filters installed. You may want to check with Tom regarding this. Or maybe someone else here might know if the natural roll-off puts undue stress on the driver at the subsonics.
-Jai


Got it....here is the convo with Ed. I think it helps explain how the Subsonic filter actually works for the PB-12NSD...

*********Room gain (theoretically a 12 dB/octave transfer function at best and usually less) can only help a bass reflex subwoofer with a high pass (subsonic) filter so much.

The subwoofer is rolling off at ~36 dB/octave below tuning, and room gain might shave-off 7-10 dB/octave, so you are still rolling off at 26-29 dB/octave, even with room gain factored in. That means your response will drop from 26-29 dB from 18 Hz to 9 Hz.************

what is meant by "pretty good protection?" does it have the same filter the pb-12 does or something else?

That's a question I've been mulling over since the comparative graphs and pondering after the responses from LowOrder, Ed and Mark. What is clear from the graphs is that implementation of the limiter is another one of those design decisions which clearly impacts performance. How much is "pretty good protection" and how much is "overaggresive protection"? Without running more tests its tough to say, but Craig was pushing both subs hard yet one did a reasonable reproduction of the soundtrack across the scene and the other compressed the 45HZ peak by a huge amount.

The question is not so much about the type of limiter or whether that limiter was functioning properly. Rather its whether the peak limiters which have adjustable parameters for attack/sustain duration and continuous/peak power levels have been "overadjusted" in the design of the PB12-NSD in trying to make it damage-proof. Yes its hard to conclude definitely but that appears to be the case based on the data and explanations provided so far. Design "flaw" or design "overcautiousness", call it what you like.

Right now, there still seems to be some confusion about the PB12-NSD. The limiter in it is not over cautious, nor is it a design flaw. There is also nothing wrong with the PB12 which we have here.

Let's check out three graphs again ... The PB12 Original, where the limiter engaged rather aggressively, the 2nd PB12 graph, where the level increase stopped just before engaging the limiter, and the VTF-3.3.

We have heard the reports that the VTF-3.3 will deliver, according to the Sensible Sound review, a high level of SPL than will a PC-Ultra.

The PC-Ultra will also deliver higher SPL than will a PB12-NSD.

When I ran these scenes, I was looking specifically at the 20 Hz region for output, and was increasing SPL until it was audibly overloading during the peak scenes.

The PB12 never had any audible distress ... so I kept increasing the SPL until it would deliver no higher dB levels @ 20 Hz.

The VTF-3.3 (and 2.3) will start to have audible distress as it nears its limits ... so you reach a point where you know "It is Time to stop".

Let's look at the graphs again, and keep in mind that the PB12 SHOULD deliver a lower level of SPL than the Turbo-equipped VTF-3.3

Original PB12-NSD graph:

http://img.photobucket.com/albums/v171/craigsub/pb12mc.jpg

VTF-3.3 with Turbo graph:

http://img.photobucket.com/albums/v171/craigsub/vtf33MCtrb.jpg

Second PB12-NSD graph. Note - This was taken AFTER the original. If the sub was not working properly, this graph would not have occured.

http://img.photobucket.com/albums/v171/craigsub/SVSPB12MCpartII.jpg

According to Howard Ferstler, when He tested the PC-Ultra, it delivered 106 dB in his room @ 20 Hz before he heard port noise. This means it may have had 1-2 dB additional SPL output before compressing ... but he stops when he hears port noise.

The VTF-3.3 delivered 112 dB with Turbo @ 20 Hz.

The first graph of the PB12-NSD has it delivering about 102 dB @ 20 Hz into our room ... vs. 104 dB for the VTF-3.3 ... Do the math, and it is pretty clear that the PB12 was being heavily taxed. Think about it ... If the PC Ultra is appx. 4 dB (an estimate) lower in SPL than is the VTF-3.3 + turbo, the PB12-NSD will be more than 2 dB lower than the Hsu.

The second graph has the PB12 delivering about 5 dB lower SPL @ 20 Hz ... and at this level the unit stay quite linear.... look at the difference in the mid bass levels.

Hopefully .. this clears up this issue.

Thanks for the explanation, craig. I thought it was clear awhile ago though. Oh well.

That's a question I've been mulling over since the comparative graphs and pondering after the responses from LowOrder, Ed and Mark. What is clear from the graphs is that implementation of the limiter is another one of those design decisions which clearly impacts performance. How much is "pretty good protection" and how much is "overaggresive protection"? Without running more tests its tough to say, but Craig was pushing both subs hard yet one did a reasonable reproduction of the soundtrack across the scene and the other compressed the 45HZ peak by a huge amount.

The question is not so much about the type of limiter or whether that limiter was functioning properly. Rather its whether the peak limiters which have adjustable parameters for attack/sustain duration and continuous/peak power levels have been "overadjusted" in the design of the PB12-NSD in trying to make it damage-proof. Yes its hard to conclude definitely but that appears to be the case based on the data and explanations provided so far. Design "flaw" or design "overcautiousness", call it what you like.

Exactly, John.

Any OEM walks a fine line with respect to limiter adjustment. We can clamp down on the limiters to make any powered subwoofer bullet-proof, but that does shave off some available headroom. Conversely, we can loosen the limiters to let the sub run full-bore, but that means it can be overloaded and/or bottomed under very heavy use.

We rely to some extent on the customer to notice impending signs of overload - dynamic compression, cone cry, port chuffing - before the subwoofer actually hard bottoms.

We also try very hard during the pre-sale stage to match the right subwoofer to the specific application, room size, and preferred listening level so the subwoofer is always operating within its clean/linear limits even at the highest expected playback level.

The laws of variability being what they are - we erred on the side of caution with the PB10-NSD and PB12-NSD when it came to limiter tweaking. :)

Got it....here is the convo with Ed. I think it helps explain how the Subsonic filter actually works for the PB-12NSD...

*********Room gain (theoretically a 12 dB/octave transfer function at best and usually less) can only help a bass reflex subwoofer with a high pass (subsonic) filter so much.

The subwoofer is rolling off at ~36 dB/octave below tuning, and room gain might shave-off 7-10 dB/octave, so you are still rolling off at 26-29 dB/octave, even with room gain factored in. That means your response will drop from 26-29 dB from 18 Hz to 9 Hz.************
So in effect it behaves like a 4th order filter. It is still not clear to me if that frees up the driver from those really low frequencies.
Ed,
Will using a subsonic filter at 16Hz give more headroom and better performance for bgilly at higher frequencies?
Thanks,
-Jai

How does this explain Craig's graphs that show the PB12 before the limiter kicks in as having higher SPL in the mid base region? Shouldn't the limiter just limit power output at some level instead of reducing it when a level is exceeded?

Why not add another switch for the user to adjust the limiter to Max. Protection, Normal Protection, and Min. Protection. Just add a strong warning to the manual and put a stringed warning tag (like the one included on those with subsonic filters), and let the end user decide?

How does this explain Craig's graphs that show the PB12 before the limiter kicks in as having higher SPL in the mid base region? Shouldn't the limiter just limit power output at some level instead of reducing it when a level is exceeded?

Why not add another switch for the user to adjust the limiter to Max. Protection, Normal Protection, and Min. Protection. Just add a strong warning to the manual and put a stringed warning tag (like the one included on those with subsonic filters), and let the end user decide?


Well i know why they didn't add another switch or 2 or 3.....

$$$$$$$$$ They are trying to keep the price down, every feature you add in addition to what is already there costs more money for them, and then they would have to turn around and raise the price for the public, and thus the PB-12NSD would not be priced at $599....

So in effect it behaves like a 4th order filter. It is still not clear to me if that frees up the driver from those really low frequencies.
Ed,
Will using a subsonic filter at 16Hz give more headroom and better performance for bgilly at higher frequencies?
Thanks,
-Jai

Right, in-room roll-off is ~24-30 dB/octave (4th-5th order) below Fb, depending on the extent of room gain.

Using a deeper high pass filter will actually reduce available headroom because a bass reflex alignment becomes undamped below Fb and the woofer excursion is no longer well controlled. The correct setting for a high pass filter is just below Fb.

How does this explain Craig's graphs that show the PB12 before the limiter kicks in as having higher SPL in the mid base region? Shouldn't the limiter just limit power output at some level instead of reducing it when a level is exceeded?

Why not add another switch for the user to adjust the limiter to Max. Protection, Normal Protection, and Min. Protection. Just add a strong warning to the manual and put a stringed warning tag (like the one included on those with subsonic filters), and let the end user decide?

The limiter behavior will change based on the amplitude and duration of the signal, the input voltage, and the total power demands being place on the amplifier. It might allow a peak to pass unfettered at a certain drive level and then react completely differently on the same passage at a higher drive level.

Anyone with experience in tweaking limiters knows it's half science and half black art; there are too many parameters to simplify them to a 3 position switch, although I can appreciate the concept.

Exactly, John.

Any OEM walks a fine line with respect to limiter adjustment. We can clamp down on the limiters to make any powered subwoofer bullet-proof, but that does shave off some available headroom. Conversely, we can loosen the limiters to let the sub run full-bore, but that means it can be overloaded and/or bottomed under very heavy use.


I really have to say that the term 'Any OEM' is stretching it, in this context.

The ported alignment is less expensive to build and offers added output across one of it's octaves, but...it's much harder to balance amplifier power/limiters/filter protection/tune/box size/driver within a smaller budget.

IOW, the line only becomes a fine line when you begin to paint yourself into the bang-for-buck ported corner, which of course does not include every OEM.

If you look at the JL Fathom as an example: 2.5KW, 50mm of available one way travel and a sealed alignment rolled into a pretty darned great balance of power/driver/alignment/box size.

The truth is that it's much easier, when you have the proper budget and alignment, to hit the sweet spot without aggressive use of any sorts of electronic brakes, IMHO.

Bosso

Ed and Bosso ... perhaps we could change "any OEM" to "any OEM looking to deliver a good performer and keep the cost to $599" ... Bosso suggests this point in his post, but I thought some clarification might be helpful.

Ed ... Now that CES is over ... when can we expect more news on the new Ultra ?

nm :rolleyes:

SbWillie, those are the dual driver cabinets Tom was talking about not being available until Q3 -- the single driver cylinder and box will hopefully ship by May (my guess), with preorders starting late March/early April.

Ed and Bosso ... perhaps we could change "any OEM" to "any OEM looking to deliver a good performer and keep the cost to $599" ... Bosso suggests this point in his post, but I thought some clarification might be helpful.


Forgive my 'vagueness gene' flaw. You nailed it. :)

Bosso

your right..I posted too quick.

Hang in there and keep it up CRAIG! There are many out here that love ya man!

Mike L.

Exactly, John.

Any OEM walks a fine line with respect to limiter adjustment. We can clamp down on the limiters to make any powered subwoofer bullet-proof, but that does shave off some available headroom. Conversely, we can loosen the limiters to let the sub run full-bore, but that means it can be overloaded and/or bottomed under very heavy use.

We rely to some extent on the customer to notice impending signs of overload - dynamic compression, cone cry, port chuffing - before the subwoofer actually hard bottoms.

We also try very hard during the pre-sale stage to match the right subwoofer to the specific application, room size, and preferred listening level so the subwoofer is always operating within its clean/linear limits even at the highest expected playback level.

The laws of variability being what they are - we erred on the side of caution with the PB10-NSD and PB12-NSD when it came to limiter tweaking. :)

Given where these subs are in the lineup and their price points, I understand wisely erring on the side of caution. Presumably other subs in the product line would have different limiter characteristics. In the absense of the limiter kicking in, that scene would have bottomed the sub seeing how much it was being overdriven. A bottoming sub in an intense scene ruins the impact of the movie. Better a limiter take over and most users would never notice.

The limiter behavior will change based on the amplitude and duration of the signal, the input voltage, and the total power demands being place on the amplifier. It might allow a peak to pass unfettered at a certain drive level and then react completely differently on the same passage at a higher drive level.

Anyone with experience in tweaking limiters knows it's half science and half black art; there are too many parameters to simplify them to a 3 position switch, although I can appreciate the concept.

A black art indeed where the designer's judgement and ingenuity are relied upon when deciding when/how to limit in light of other design targets and amp properties . :cool: Many users like to run these subs very hot, 5-10db or more, which further increases the likelhood of bottoming in those scenes. Limiter implementation is not an area that has been analyzed much in these comparisons or in other threads. Seeing how much they impact headroom, it would be worthwhile to examine this area more closely. It also means yet more caution when interpreting the peak hold graphs presented here for comparisons.

Given where these subs are in the lineup and their price points, I understand wisely erring on the side of caution. Presumably other subs in the product line would have different limiter characteristics. In the absense of the limiter kicking in, that scene would have bottomed the sub seeing how much it was being overdriven. A bottoming sub in an intense scene ruins the impact of the movie. Better a limiter take over and most users would never notice.



A black art indeed where the designer's judgement and ingenuity are relied upon when deciding when/how to limit in light of other design targets and amp properties . :cool: Many users like to run these subs very hot, 5-10db or more, which further increases the likelhood of bottoming in those scenes. Limiter implementation is not an area that has been analyzed much in these comparisons or in other threads. Seeing how much they impact headroom, it would be worthwhile to examine this area more closely. It also means yet more caution when interpreting the peak hold graphs presented here for comparisons.

Good points ... especially about interpreting the results. My new laptop got a crack in the screen, thanks to a kid's great aim with a football. No, it wasn't my kid, either. And the parent's response was: "Why would you leave a laptop open with 8 kids in your house"

It never occured to this genius parent that his kid was at fault ... :rolleyes:

Anyway, when I get it back, the latest TrueRTA software is on it, and I want to run some more movie scenes showing response to 100 Hz.

Geez. Some neighbour. :eek: I'm surprised he didn't offer to repair it if it was his kid. Maybe you should send him the bill anyway.

Given where these subs are in the lineup and their price points, I understand wisely erring on the side of caution. Presumably other subs in the product line would have different limiter characteristics. In the absense of the limiter kicking in, that scene would have bottomed the sub seeing how much it was being overdriven. A bottoming sub in an intense scene ruins the impact of the movie. Better a limiter take over and most users would never notice.

I differ. I prefer a sub that bottoms out to one that sacrifices head room due to a stringent limiter. One could always use the "sub peak limiter" on their receiver/pre-amp once they know the limitations of their sub or better I would know it's time to add more subs. Does not mean I am ok with subs bottoming out. A limiter is almost like a rev limiter in a hot rod peformance car or a watts/centrifugal governor. In short, I prefer "do or die" :D. I hate limiters that kick in too early. That's just me and opinions may vary widely.
-Jai

I have to admit to defeating the limiters on my own subs. I've championed the idea of a limiter defeat control during NPI meetings but that kind of laissez faire gave paroxysms of spasms to management. I'm currently looking at an electronic risk manager algorithm that registers abuse level and ACTIVATES soft clipping and harmonic suppression only when truly needed. A secondary but important function is a gain INCREASE based on thermal modeling of the voice coil to compensate for power compression at higher outputs, with a reduction in limiting threshold to control peak heating of the voice coil materials.

So maybe we should be asking ourselves, what is it about conventional subwoofer setups that MAKES US WANT TO RUN THEM 5-10dB hot? If we could solve some underlying basic flaws in virtually every sub made, we might not be fighting the limit points so hard.

:p

How does this explain Craig's graphs that show the PB12 before the limiter kicks in as having higher SPL in the mid base region? Shouldn't the limiter just limit power output at some level instead of reducing it when a level is exceeded? Why not add another switch for the user to adjust the limiter to Max. Protection, Normal Protection, and Min. Protection. Just add a strong warning to the manual and put a stringed warning tag (like the one included on those with subsonic filters), and let the end user decide?

One of Craig's graphs for an SVS sub showed a huge drop at 45 hz, which lead to the 14.5-18.5 dB deficit to a Hsu. Has anyone else duplicated Craig's huge output drop, the one pointed out by "RossandWendy" recently? At that frequency it would seem like the sub was turned off given the huge dB change that came on so very suddenly, per Craig's tests. I may have missed it but I have not seen a credible explanation for this effect. At least one more experienced reviewer didn't find anything like this dB drop I am informed.

I see nothing *wrong* in the behavior observed and questioned in the PB12-NSD. The observation is very much as Craig noted, where the other subs hit some wall before a limiter can get aggressive enough to compress peaks like this. (

It didn't compress peaks as much as dropping output way, way below the just-prior output as the input level was increased 3 dB. In other words the sub did not just stop getting louder, it got way quieter than prior. Per Craig. He showed graphs indicating a 14.5 - 18.5 dB deficit to a comparable subwoofer.

How Old are you???? Who in their adult mind would spell the words how come as howcum. There is no way that an intelligent ADULT can misspell the word COME for CUM.... I'm seriously doubting any thread of intelligence on your end, rather, just the need to spark doubt on things and stir up problems. If you don't like my posts....then please leave! :D

I'm in my 40s. How about you? Ever hear of slang or other casual word useage?

Intelligence? I have no worries there.

Now, you are asking a member to leave, if they don't like your posts. If posts like yours are okay here then that is just part of the AVS experience. Yours seems to be an off topic post too.

It didn't compress peaks as much as dropping output way, way below the just-prior output as the input level was increases 3 dB. In other words the sub did not just stop getting louder, it got way quieter. Per Craig. He showed graphs indicating a 14.5 - 18.5 dB deficit to a comparable subwoofer.

It is pretty clear you don't know how this could happen. Nor are you accurate in stating what DID happen here. However, since you mentioned another reviewer ... let us be precise here and use your exact words ... At least one more experienced reviewer didn't find anything like this dB drop I am informed.

What did this anonymous reviewer test ? Do you have a link ?

It is pretty clear you don't know how this could happen. Nor are you accurate in stating what DID happen here. However, since you mentioned another reviewer ... let us be precise here and use your exact words ... What did this anonymous reviewer test ? Do you have a link ?

I am not sure if the review has come out yet. It's one I've been told about. I'll post a link if one is available.

I am not sure if the review has come out yet. It's one I've been told about. I'll post a link if one is available.

just curious - care to share details on how you obtained the information?

It is pretty clear you don't know how this could happen. Nor are you accurate in stating what DID happen here.

Craig, why not simply do a more careful test of the sub that dropped so much output when it was turned up? This does not have to remain so fuzzy.

I am not sure if the review has come out yet. It's one I've been told about. I'll post a link if one is available.

And this reviewer attempted to replicate the identical style of test that we did here ? This should be good.

And this reviewer attempted to replicate the identical style of test that we did here ? This should be good.

I doubt he attempted to replicate what you do. Why would he do that? He did his normal, credible tests. And he used the sub without running across the behavior you have noted.

Craig, why not simply do a more careful test of the sub that dropped so much output when it was turned up? This does not have to remain so fuzzy.

The fact that you even are asking this question defies logic. You are the one person who does not seem to "get" what the testing here showed. It truly is not difficult for a reasonable person to read each graph, and the discussion about how each graph was taken, to understand what was occuring in each.

The amount of reduction does seem curiously high, and should be examined to be explained, but it isn't necessarily impossible.

Exactly! Let's see more on this sub's behavior.

I am concerned that if a member questions these tests they get attacked. That is unfortunate and raises many questions.

I doubt he attempted to replicate what you do. Why would he do that? He did his normal, credible tests. And he used the sub without running across the behavior you have noted.

If someone did not attempt to do what we did here, then how COULD he run across the behavior the graph here showed ?

Stan, You won't find where I "claim" anything. What you will find is 2 TrueRTA graphs of the Master & Commander scene on the PB12-NSD.

The graphs to which I refer are the ones that "RossandWendy" brought up recently with the 14.5-18.5 db comments. Which you supported at the time. Then you did a retest stating that you'd verified your tests.

Exactly! Let's see more on this sub's behavior.

I am concerned that if a member questions these tests they get attacked. That is unfortunate and raises many questions.

I have posted additional information on the sub's behavior. I also ran the test again, stopping before we got to heavy limiting. That graph was then posted. You asked for further clarification. You got it, and yet you are still complaining about being attacked.

If someone did not attempt to do what we did here, then how COULD he run across the behavior the graph here showed ?

Craig, the world does not revolve around you! These are tests performed late last year. How could they anticipate your results on your sample of the sub in order to respond to this thread? They simply did their normal battery of use and test efforts, that is all.

Craig, the world does not revolve around you! These are tests performed late last year. How could they anticipate your results on your sample of the sub in order to respond to this thread? They simply did their normal battery of use and test efforts, that is all.

This is your quote:

One of Craig's graphs for an SVS sub showed a huge drop at 45 hz, which lead to the 14.5-18.5 dB deficit to a Hsu. Has anyone else duplicated Craig's huge output drop, the one pointed out by "RossandWendy" recently? At that frequency it would seem like the sub was turned off given the huge dB change that came on so very suddenly, per Craig's tests. I may have missed it but I have not seen a credible explanation for this effect. At least one more experienced reviewer didn't find anything like this dB drop I am informed.

YOU said the reviewer did not find anything like we did. This suggests he attempted to find something like we did here.

I have posted additional information on the sub's behavior. I also ran the test again, stopping before we got to heavy limiting. That graph was then posted. You asked for further clarification. You got it, and yet you are still complaining about being attacked.

If a reviewer wishes to be credible, respected, helpful, etc, they can try to answer questions in an open and respectful manner. I have been attacked here, that is clear.

I can tell you that through PMs and email I have received many supportive comments about this situation. Many note that they don't want to post as they do not want to be attacked by those in such threads with agendas or a tendency to do so. Some are active posters, some are lurkers. Some have run into your reviews in other places.

If a reviewer wishes to be credible, respected, helpful, etc, they can try to answer questions in an open and respectful manner. I have been attacked here, that is clear.

I can tell you that through PMs and email I have received many supportive comments about this situation. Many note that they don't want to post as they do not want to be attacked by those in such threads with agendas or a tendency to do so. Some are active posters, some are lurkers. Some have run into your reviews in other places.

Ok Stan ... Once again we get into the mystery PM's. :rolleyes:

In the meantime, have you bothered to look at the 2 graphs of the PB12-NSD ? If not, then perhaps you should. If you have, some real comments about the 2 graphs, from you, would be interesting.

I can tell you that through PMs and email I have received many supportive comments about this situation. Many note that they don't want to post as they do not want to be attacked by those in such threads with agendas or a tendency to do so. Some are active posters, some are lurkers. Some have run into your reviews in other places.
I have had my doubts about craig before too...and might again one day as well. But to post something like that is absolute chicken sh*t by you and people allegedly sending you the PM's and email.

Do you guys remember when a company tried to scare me by threatening legal action over a post I made? It reminds me of that crap.

sjmarcy,

If this "reviewer," in the course of his "tests," did not test for max output using frequency peak holds, looking for compression at high volume levels, then it is no surprise that the person did not find the same results.

Even if the 45Hz range were to drop drastically, by 15dB, taking a general SPL reading would not show a drop of 15dB, because the rest of the frequencies are still as loud or louder.

The original graph was posted, follow-up tests were done at basically your request, showing that the drop in dB at 45hz was found when the subwoofer was pushed, resulting in its limiter kicking in. It was verified that the SPL returned at 45hz when the volume level was backed off a bit. Confirmed again and again that this was due to the limiter.

So please explain what exactly your problem is, because everything you brought up originally about the test has been covered and explained and re-tested.

And please stop complaining about being attacked. That has nothing to do with craigsub himself. Other members are free to post as they wish, in any manner and tone they wish. If you encounter problems, please discuss it with the moderators.

I have had my doubts about craig before too...and might again one day as well.

You mean ... for example ... if the new Ultra bests the VTF-3 HO in that comparison ? :D (this was humour, guys. Seriously, though ... trust can take some time to build up ... and even trust does not mean agreeing on everything)

I feel Ed gave an adequate explanation about the PB12's limiter and how it could have effected Craigs measurements. To validate this, you could measure progressively louder sweeps or pink noise until the limiters kick in. If the output above 40 Hz drops from the unlimited tests, then that would substantiate Ed's comments and Craig's measurements.

Stan, ask TomV to loan you a PB12 and run your own tests, then post here.

If it is shown to be the limiters and they do actually reduce output instead of just limiting additional output, then the next question would be to ask SVS or BASH why they employ such aggressive limiting circuits.

Next would be to run the same tests on the +/2 and see if it behaves the same way. That would disclose if overly aggressive limiters are deployed in other SVS/BASH subs or if this is an anomaly in the PB12-NSD.

You mean ... for example ... if the new Ultra bests the VTF-3 HO in that comparison ? :D (this was humour, guys. Seriously, though ... trust can take some time to build up ... and even trust does not mean agreeing on everything)
:D Too funny!

I read about how much more supposed output the new Ultra will have.....if I what read is correct, it puts it in the area of the 3.3 w/turbo...at least in the deep bass. Who knows until it is tested?

Then again, you know I don't care about output as much as sound quality...and this is where the two companies' philosophies have created very different results IMO. I am actually thinking about trying to build a sealed sub.

I feel Ed gave an adequate explanation about the PB12's limiter and how it could have effected Craigs measurements. To validate this, you could measure progressively louder sweeps or pink noise until the limiters kick in. If the output above 40 Hz drops from the unlimited tests, then that would substantiate Ed's comments and Craig's measurements.

Stan, ask TomV to loan you a PB12 and run your own tests, then post here.

If it is shown to be the limiters and they do actually reduce output instead of just limiting additional output, then the next question would be to ask SVS or BASH why they employ such aggressive limiting circuits.

Next would be to run the same tests on the +/2 and see if it behaves the same way. That would disclose if overly aggressive limiters are deployed in other SVS/BASH subs or if this is an anomaly in the PB12-NSD.

While comparing to the +/2 seems like a good idea, in practice I have found that bottoming the plus/2 is possible ... Neither the PB10 nor the PB12 NSD could be bottomed, regardless how hard I beat on them.

And ... let's review the actual posts, and also some facts.

Here is what I said last Sunday night about the PB12-NSD's graph

While doing these tests, the area being observed was the 15 to 30 Hz area, for maximum output, and the subwoofers were being increased 3 dB at a time, with about 120 seconds between tests, until compression set in. It is likely that the limiters were causing some of the differences we are seeing in that 40-45 Hz area.

I would not be surprised to see the PB12-NSD to have a higher SPL ability @ 45 Hz when not pushing the subwoofer quite so hard. I will run some graphs again tomorrow, and see what happens.

:D Too funny!

I read about how much more supposed output the new Ultra will have.....if I what read is correct, it puts it in the area of the 3.3 w/turbo...at least in the deep bass. Who knows until it is tested?

Then again, you know I don't care about output as much as sound quality...and this is where the two companies' philosophies have created very different results IMO. I am actually thinking about trying to build a sealed sub.

Ed Mullen also mentioned that SQ is going to be improved on the new Ultra - not that the old Ultra was a problem in that area.

That could be the right time for another GTG ... getting several AVSers here for a blind test between the new Ultra and the VTF-3 HO/Turbo is a must do.

Then that begs the question as to why SVS/BASH would utilize such overly aggressive limiters (as I see it). Shouldn't they just limit output and not reduce it? If they do need to back down the output, why so much?

That could be the right time for another GTG ... getting several AVSers here for a blind test between the new Ultra and the VTF-3 HO/Turbo is a must do.
Yes....and it will be warmer in your neck of to woods too. :)

Craig, isn't it time to go to the next subs. 30 pages and I think you have only done 3 subs. Many are awaiting the Fathom. I'm interested in what you are going to put up as the challengers. I thought for sure you would bring back the Maestro for this. Especially if it is going to be a while before you can get a Submersive. Do you still have the DD18?

Craig, why not simply do a more careful test of the sub that dropped so much output when it was turned up? This does not have to remain so fuzzy.


I have an Idea....you should buy some of these subs with your own money, do the tests the way you want them done, and then we can have even more data to compare with Craigs :)

Then that begs the question as to why SVS/BASH would utilize such overly aggressive limiters (as I see it). Shouldn't they just limit output and not reduce it? If they do need to back down the output, why so much?

SVS is not using overly aggressive limiters, IMO. The limiter is there to protect the driver, and it does its job very well. With some careful "runs", I was able to get the PB12-NSD to deliver 101 dB in that 18-24 Hz area with no severe attenuation of the 45 Hz signal.

Keep in mind, the subwoofer is trying to reproduce several frequency bands at once, and these are under rapidly changing conditions ... capturing the last dB of that collection of signals is very difficult... so getting the graph that shows the last dB of performance is ALSO very difficult.

Look, for example, at the VTF-2.3 Again, keep in mind I am listening for audible distortion or bottoming, and stopping the test. By its very nature of firing forward, it is easier to notice the Hsu starting to bottom with the turbo than without it.

Hsu VTF-2.3 w/o turbo:

http://img.photobucket.com/albums/v171/craigsub/MCVTF2.jpg

Hsu VTF-2.3 with turbo

http://img.photobucket.com/albums/v171/craigsub/vtf23mctrb.jpg

The lower SPL @ 45 hz is evident here, too. This does not mean the turbo assisted is delivering higher output @ 45 Hz ... but rather that the VTF-2.3 was driven more into compression @ 20 Hz in the non-turbo test than with the turbo test.

I am not sure if the review has come out yet. It's one I've been told about. I'll post a link if one is available.
As upcoming reviews are held tight between editors/reviewers and the brands CEO's its pretty obvious who told you while you have been discussing this thread.

Why not (as others have said) do your own tests in another thread.

Ddavidson

SVS is not using overly aggressive limiters, IMO. The limiter is there to protect the driver, and it does its job very well. With some careful "runs", I was able to get the PB12-NSD to deliver 101 dB in that 18-24 Hz area with no severe attenuation of the 45 Hz signal.

Keep in mind, the subwoofer is trying to reproduce several frequency bands at once, and these are under rapidly changing conditions ... capturing the last dB of that collection of signals is very difficult... so getting the graph that shows the last dB of performance is ALSO very difficult.



Craig I think what you just said speaks VOLUMES to proper calibration and knowing what the ideal listening volume is for your system. A few dbs high or low can impact the performance...

Craig I think what you just said speaks VOLUMES to proper calibration and knowing what the ideal listening volume is for your system. A few dbs high or low can impact the performance...

This also explains why adding a 2nd subwoofer is such an enhancement in the performance delivered. 6 dB is a HUGE difference, in terms of clean output.

This also explains why adding a 2nd subwoofer is such an enhancement in the performance delivered. 6 dB is a HUGE difference, in terms of clean output.


Exactly...you do not have to PUSH your single sub to its LIMIT to SLAM that 20hz bass, rather you can comfortably push 2 subs and have maximum output across all of the frequencies. The happy medium of having enough slam at 20hz and enough punch at 45hz :)

The limiters in our Indigo BASH amps will not cause a 14-18 dB (or w/e) reduction in output at any given frequency. If the sub is severely overdriven, it's possible for the output to drop below what was previously attainable at a lower drive level, but it won't drop that much.

The PB12-Plus in the 16 Hz tune exhibited this type of behavior during output compression sweeps. I used 2 dB sweep increments on this particular sub test. Notice at the highest sweep level (green line), the limiter kicks in just below 20 Hz, and the output drops below the previous sweep level (purple) to approximately equal the amplitude of the next lower sweep (yellow). This is a drop of about 4 dB total (i.e., about two sweep levels).

http://www.hometheaterhifi.com/volume_13_1/svs-pb12-plus-subwoofer-1-2006-part-3.html

This represents a worst-case scenario when it comes to a limiter "over-reacting" for lack of a better term. On short-term transients, the limiter activity will be less aggressive. Also, the limiter isn't "band-sensitive", either. If it senses the amp clipping, or it senses a too-high input voltage, it lowers the overall output level until the condition passes (attack/release times); it is not capable of "targeting" a certain portion of the pass-band.

Hi Ed,

It's important to note that the reason the "green" sweep only falls behind -4dB below 20Hz is due to some possible element of GAIN in the system for low frequency assistance? Alternatively, the limiter maybe has a frequency shaping network on the control signal side, and makes inputs below 20Hz more strongly limit the whole band than inputs well above 20Hz in frequency. Thus the sweep nature of the test signal HIDES compression of the whole bandwidth in the presence of strong information below 20Hz.

I suspect that the scene Craig is using for his AVERAGE ENERGY has a particular order of appearance of tones, such that significant energy in the 45Hz band comes on the heels of some crazy tones below 20Hz. So you would get:

#1 20Hz wallop

#2 some 45Hz info -4dB down

But the stuff before and after stays at a decent level, unsquashed by the limiter away from the big bang at <20Hz. There is some danger using sweeps because the simplified nature of the input signal may hide complex behavior. That said, it isn't a severe error, but a larger one than the high-to-low frequency "green" sweep suggest. I'm impressed Craig's alternate methodology has added a tool for quantifying dynamic signal behavior of limiters.

It would be fun if Craig cut us a 10 second MP3 of sections he is using, so we could do a better analysis of the signal order, and listen to it on our own systems. He might not get sued for copyright, as I recall something about the sampling limit being 10 seconds.

:)

A bump as I asked this question during the most turbulent and most OT part of this thread...any opinions would be greatly appreciated.

Everyone,

Any opinions on the Martin Logan series of subwoofers? I have a Grotto and I love it, but its very tight and does not overwhelm me with its power. It is 250W RMS (22-150hz). I was thinking about running another sub off the analogs from the Grotto (sub out too). Sound like a good idea?

What are your opinions (if any) of the Grotto? What would be a good companion sub?
What do you think of the Descent? P.S. Money is a concern, the Descent is just a dream right now. I got the Grotto for music (I feel it was worth it, but was fairly expensive nonetheless), this sub would drive HT needs primarily with music comprising close to 35% (vinyl and CD).

Thanks for the info I've gotten so far.

Hi Ed,

It's important to note that the reason the "green" sweep only falls behind -4dB below 20Hz is due to some possible element of GAIN in the system for low frequency assistance? Alternatively, the limiter maybe has a frequency shaping network on the control signal side, and makes inputs below 20Hz more strongly limit the whole band than inputs well above 20Hz in frequency. Thus the sweep nature of the test signal HIDES compression of the whole bandwidth in the presence of strong information below 20Hz.

I suspect that the scene Craig is using for his AVERAGE ENERGY has a particular order of appearance of tones, such that significant energy in the 45Hz band comes on the heels of some crazy tones below 20Hz. So you would get:

#1 20Hz wallop

#2 some 45Hz info -4dB down

But the stuff before and after stays at a decent level, unsquashed by the limiter away from the big bang at <20Hz. There is some danger using sweeps because the simplified nature of the input signal may hide complex behavior. That said, it isn't a severe error, but a larger one than the high-to-low frequency "green" sweep suggest. I'm impressed Craig's alternate methodology has added a tool for quantifying dynamic signal behavior of limiters.

It would be fun if Craig cut us a 10 second MP3 of sections he is using, so we could do a better analysis of the signal order, and listen to it on our own systems. He might not get sued for copyright, as I recall something about the sampling limit being 10 seconds.

:)

Yes - I only used the compression sweep graph only to illustrate that the limiter can - under certain circumstances - reduce output to below what was previously attainable at a lower input drive level, but that it won't drop 14-18 dB.

For another example, Ilkka's compression tests of the Plus/2 in the 20 Hz tune show limiter activity in the 30-40 Hz region. Note on the "110 dB" red curve, the amp suddenly clips (thus spiking THD) and the limiter clamps down hard.

Conversely, on the "115 dB" pink sweep level, the limiter kicks in earlier at 40 Hz and you can see the attack/release behavior as the THD fluctuates up/down (but the amp remains below clipping) and the overall output then remains suppressed for the entire remainder of the sweep, in some cases falling to equal or slightly below the previous sweep level (about a 5-6 dB reduction in output).

These two sweeps show different types of limiter behavior - both of which are normal and consistent with my own testing on the PB12-Plus, albeit occuring at different frequencies in the pass band.

http://www.hometheatershack.com/forums/subwoofer-tests/996-svs-pb12-plus-2-20-hz-plus-12-3-a.html

You are most certainly correct that there are other tests (like those I enumerated earlier in this thread) that one could run to expose different types of subwoofer behavior when overdriven. Pink noise, multi-tone sines, tone bursts, or even real source material.

There is a specific EQ curve for the 16 Hz tune switch setting, but it only affects limiter activity to the extent that additional EQ boost can cause the amp to clip sooner than might otherwise occur without EQ. The PB12-Plus limiter clamped down in the 16 Hz tune at/near Fb (~16-17 Hz but it varies with the amount of port compression which is occuring), where impedance is low and current draw on the amp is quite high. But the limiter is not band-specific and it does not target certain bandwidths more than others - it is strictly triggered by amp clipping or exceedances of input voltage pre-sets. For more information, I suggest contacting BASH Audio directly.

Thanks for the clarification Ed.

I'm giggling now because of the impulse response graph posted by Ilkka Rissanen! It looks like it was overlayed off by a full cycle. That low "overshoot" is in this case impossible, but instead represents the first impulse cycle that any ported box near the tuning frequency simply cannot play at full level. It is particularly interesting since I have a theory that human beings will unconsciously modify data to fit a preconceived notion of correct performance. In this case the graph ends up being just such an "invention". I've even had it happen to me once or twice!

Seriously, more attention needs to be payed to bass fidelity beyond the static frequency response and THD related to those steady sine tones. Despite the short shrift given to impulse correct behavior, I count it as possibly the MOST important parameter under dynamic signal conditions.

;)

Thanks for the clarification Ed.

I'm giggling now because of the impulse response graph posted by Ilkka Rissanen! It looks like it was overlayed off by a full cycle. That low "overshoot" is in this case impossible, but instead represents the first impulse cycle that any ported box near the tuning frequency simply cannot play at full level. It is particularly interesting since I have a theory that human beings will unconsciously modify data to fit a preconceived notion of correct performance. In this case the graph ends up being just such an "invention". I've even had it happen to me once or twice!

Seriously, more attention needs to be payed to bass fidelity beyond the static frequency response and THD related to those steady sine tones. Despite the short shrift given to impulse correct behavior, I count it as possibly the MOST important parameter under dynamic signal conditions.

;)

Impulse response, phase response (and group delay), and 3-D spectral decay are really all ways to illustrate/describe the same phenomenon - and that is latent energy release (ringing) in the time domain.

The extent of same is largely a function of the F6 bandwidth and the slope of the roll-off. Subwoofers essentially behave like high pass filters at/near roll-off and their behavior in this respect is thus predictable. A subwoofer with a sharp knee (narrow F6 bandwidth), and a steep roll-off will ring longer than one with a wide F6 bandwidth and a gradual roll-off. A true low-Q 2nd-order sealed subwoofer (for example) will exhibit nearly perfect transient behavior in the time domain.

As upcoming reviews are held tight between editors/reviewers and the brands CEO's its pretty obvious who told you while you have been discussing this thread. Why not (as others have said) do your own tests in another thread. Ddavidson

?!?!?

It's an already published review, I located the URL pretty easily just now. So can you. You can take a look at:

http://www.soundandvisionmag.com/speakers/1962/svs-sbs-01-home-theater-speaker-system.html

Bear in mind that experienced reviewers test and listen for more things than get published. A 14-18 dB drop when the limiter kicks in was not found. Maybe the S&V reviews have some issues? I note that their recent tests of a JL F112 sub showed it did not have much deep, clean bass. It maxed out at 80 dB at 16 hz. Maybe this unit is much less capable than the larger unit.

That leaves Cragsub as the only reviewer noting this problem. If we look into the matter further as to how he found such gigantic drops in output from a particular device it would help out the group is my view. Maybe Tom Nousaine needs to greatly revise his battery of tests? Or maybe the unusual behavior was a measurement issue. Or perhaps it's just not a real issue for some reason. We haven't enough information to know this.

However, if as I have asked repeatedly, Craigsub's procedures and processes were sufficiently documented such that others can repeat the test to confirm his discovery...this would be helpful and informative. I am happy to test the exact sub he tested, but this offer was apparently declined.

If the behavior observed is supposedly not correct, why hasn't anyone from SVS recommended that craigsub send the "problem" sub back and have it replaced with a new one that works as is it supposed to? I find this very odd...

I am happy to test the exact sub he tested, but this offer was apparently declined.

And you seem to have declined to test one yourself paid for with your own money. There's a 30-day return period, so you wouldn't be out much $. Or you could go to his house and see the test performed in person. That would seem more logical than asking someone to ship his sub to you so you can test it because you don't believe the results of the test.

And you seem to have declined to test one yourself paid for with your own money. There's a 30-day return period, so you wouldn't be out much $. Or you could go to his house and see the test performed in person. That would seem more logical than asking someone to ship his sub to you so you can test it because you don't believe the results of the test.

Why would I need to do that? I am not an "Official" subwoofer reviewer.

Also, if you are trying to get to the bottom of an unusual issue it might make sense to OPENLY look into the matter. It would be necessary to have the device in question. But this device is not available to others! It would be nice to compare it to a known properly performing device, another sample. And it would help to have dialog with the official reviewer as well as the manufacturer. Come to think of it maybe a few testers should be involved. Other stuff. Including the blind test information and procedures for these reviews. Perhaps some of the participants could comment here. Was this "limiter" issue of audible significance to them? Was it tested?

For starters, complete test information would help. Maybe Craigsub contacted the manufacturer already as to this unusual 14-18 dB attenuation issue, I may have missed his comments in these regards. From the comments I see here, it seems like the manufacturer does not think the device should be cutting 14-18 dBs of output when the limiter kicks in.

And you seem to have declined to test one yourself paid for with your own money. There's a 30-day return period, so you wouldn't be out much $. Or you could go to his house and see the test performed in person. That would seem more logical than asking someone to ship his sub to you so you can test it because you don't believe the results of the test.

Seriously, just BUY some subs and test them....you can even return them like mentioned!

OR

HELL if you have the equipment and everything you need to test with I will invite you over my house, we can have a get together and test the **** out of my PB-12NSD.


PS...your "official" comment was not needed, its things like that that get us all fired up at you. Its called the official craigsub list because it was the list copied from another forum. It has nothing to do really with Craig being official or not official!

PS...your "official" comment was not needed, its things like that that get us all fired up at you. Its called the official craigsub list because it was the list copied from another forum. It has nothing to do really with Craig being official or not official!

So this is not "Official", ha? Thanks for clarifying the matter. Calling it official seems misleading to me. The admins I corresponded with did not clarify this point.

Why would I need to do that? I am not an "Official" subwoofer reviewer.



Neither is craig. And yet you hold him to professional standards, and ask him to send you HIS OWN sub. Same thing. You want to test it yourself, test a different one of the same model. Simple as that.


Also, if you are trying to get to the bottom of an unusual issue it might make sense to OPENLY look into the matter. It would be necessary to have the device in question. But this device is not available. It would be nice to compare it to a known properly performing device, another sample.


And out of all your advice, you haven't suggested sending it back or trying another one. Neither has SVS.

And it would help to have dialog with the official reviewer

There is no "official reviewer," if you will kindly recall. This is one man doing this as a hobby and sharing graphs and impressions with everyone else.


It is odd that you are more bent out of shape about the SVS's performance than SVS themselves. If it's not expected behavior, why haven't they chimed in and said so and offered to give him a new sub that performs to spec?

So this is not "Official", ha? Thanks for clarifying the matter. Calling it official seems misleading to me. The admins I corresponded with did not clarify this point.


This has been explained several times to you. This is the "official" thread for craig's "impressions" and graphs, results, etc., started by someone completely other than craig himself.

I think I'm going to start the
""Official" "Official" subwoofer testing thread conducted by those who choose to buy the subwoofers and test them solely because they love doing it.


CRAIG will be the first poster I hope :D

In the real world, circuits go through revisions, and pick and place machines get loaded with the wrong parts. I'm starting to suspect that there may be differences between the average sub of the model Craig has been working with, and HIS SPECIFIC UNIT. In that sense sjmarcy has brought up a good issue, that more data points might confirm or reject this being a model-wide issue.

My thinking has evolved to this point on subs. In order to make certain things start to really work in the bass-head's favor, we should be thinking in terms of PERCENT OF ROOM VOLUME MODULATION. The sad fact is, one 12", 15", 18" simply has near-zero coupling to the acoustic load of 15PSI air at frequencies below 40Hz or so. Even when you add in ports, the theoretical surface only doubles. Relying on room gain to boost bass performance actually smears transient pressures into multi millisecond slop, ruining the chance of summing with higher harmonics from an actual sound source (some people call this "integration"). Have you guys ever noticed the Thiel/Small parameters changing for multiple subs in a co-located position? I see the industry moving towards ever longer throws and lower efficiency, needing killoWatt amplifiers to get them moving, and truly monstrous costs to produce drivers with greater than 1" Xmax. Unless some kind of positional servo is applied, suspension non-linearities get worse with throw distance. Servo circuits introduce group delay, as do AtoD & DSP to DtoA front ends.

The solution? An assload of drivers! Instead of fighting at the edge of physics, take that same 1000Watt amp and run it into eight 12" drivers with more reasonable proportions of voice coil length, stupid big magnets, and nice rise and settling times in 0.5Qb - 0.707Qb. Let magnets do some of the work for you. A small part of me admires the engineering effort and manufacturing skill put into drivers from firms like TC sounds and Adire, but enough is enough. The law of diminishing returns is forcing us to argue that this subwoofer puts out 2dB more than that, instead of talking about 10-20dB increases through proper acoustical impedance matching. One of my larger club installations had [32] sealed 12" woofers in coffin sized boxes, covering 64 square feet of baffle area. Each enclosure had [4] drivers, and the whole bass system was run by a couple of Crown Macros. I remember subtle shifts in the position of my internal organs on the right notes in some dance music. PUT THAT IN YOUR HOUSE ALREADY! At the point that some people have dedicated rooms for theaters, making a whole wall 12" thicker and just filling it with drivers is not only practical, but seems logical to me. If your GF or wife really hates it that much, well...

I'm proposing 1% to 2% atmospheric modulation as a goal to reach truly authoritative low frequency performance. I bet you'll find that standing waves essentially go away because of the continuum of driver placement, and a certain fear of turning up your subs 12dB hot will grip your heart. Since room gain smears transients with "false" output, the new coupling will instead deliver cycle for cycle accurate SLAM, so when a dump truck falls off a bridge in some Bruckheimer flick, you'll be looking up the number to your home insurance broker to see if you've got earthquake coverage. Since you'll finally have excess bass energy to spare, one will be able to use bass traps and other room placement tricks to reduce boundary reinforcement in favor of more accurate impulse timings.

Some of the discussions on this forum remind me of VW Bug owners calling their car dealers to get upgrade suggestions so they can tow a Bayliner. In many ways, we're asking the wrong questions...

:D

Bear in mind that experienced reviewers test and listen for more things than get published. A 14-18 dB drop when the limiter kicks in was not found. Maybe the S&V reviews have some issues? I note that their recent tests of a JL F112 sub showed it did not have much deep, clean bass. It maxed out at 80 dB at 16 hz. Maybe this unit is much less capable than the larger unit.

That leaves Cragsub as the only reviewer noting this problem. If we look into the matter further as to how he found such gigantic drops in output from a particular device it would help out the group is my view. Maybe Tom Nousaine needs to greatly revise his battery of tests? Or maybe the unusual behavior was a measurement issue. Or perhaps it's just not a real issue for some reason. We haven't enough information to know this.

However, if as I have asked repeatedly, Craigsub's procedures and processes were sufficiently documented such that others can repeat the test to confirm his discovery...this would be helpful and informative. I am happy to test the exact sub he tested, but this offer was apparently declined.

Who wouldn't decline such an offer accompanied by such a supercilious tone?

This is not a knock on Tom Nousaine but anyone following the JL113 trread would know that something was amiss with TN's initial measurements, which were inconsistent with JL's tests and the reports of various posters. His results were anemic compared to the Fathom's actual output. The inital measurements were removed and replaced several weeks later with more accurate results. These things happen but no explanation was forthcoming.

Does TN need to revise his tests? Beats me. Probably not. But lets compare apples with apples.

The observed behaviour was with a movie scene with complex dynamics not a predicatable frequency sweeps which are simple crude approximations of the demands placed on subs in film soundtracks. I've seen similar reports of strange behaviour with sweeps and tones with other subs. There has been enough discussion about the limiter suggesting its implementation is overaggressive in applying brakes. At this point that would appear to be the cause of the discrepancy. It was explained well by LowOrder earlier, assuming this is still his position:


It's important to note that the reason the "green" sweep only falls behind -4dB below 20Hz is due to some possible element of GAIN in the system for low frequency assistance? Alternatively, the limiter maybe has a frequency shaping network on the control signal side, and makes inputs below 20Hz more strongly limit the whole band than inputs well above 20Hz in frequency. Thus the sweep nature of the test signal HIDES compression of the whole bandwidth in the presence of strong information below 20Hz.

I suspect that the scene Craig is using for his AVERAGE ENERGY has a particular order of appearance of tones, such that significant energy in the 45Hz band comes on the heels of some crazy tones below 20Hz. So you would get:

#1 20Hz wallop

#2 some 45Hz info -4dB down

But the stuff before and after stays at a decent level, unsquashed by the limiter away from the big bang at <20Hz. There is some danger using sweeps because the simplified nature of the input signal may hide complex behavior. That said, it isn't a severe error, but a larger one than the high-to-low frequency "green" sweep suggest. I'm impressed Craig's alternate methodology has added a tool for quantifying dynamic signal behavior of limiters

So this is not "Official", ha? Thanks for clarifying the matter. Calling it official seems misleading to me. The admins I corresponded with did not clarify this point.

sjmarcy

I don't believe that Craig even started this thread. I have been trying to figure out why you continue to agitate. Are you just going to keep it up to see how thick a skin Craig has? Or maybe to the point that he just picks up his marbles and says the heck with it? Would that be some kind of victory for you? For somebody else? I can't figure another reason. These are subwoofers. It's a hobby for crying out loud.

Ray

If you do not like what Marcy says report him.

Craig knows better than to let someone with some sort of secrete plan or something stop him from doing what he likes, which is testing his Audio Equipment. Craig knows he has a STRONG following here and we support and THANK him for everything he does that we all wish we could do!

LowOrder,

32 sealed 12" subs in coffinsized boxes? Sign me UP!! :D

That's gotta be one serious setup. :eek: Yet another system for me to be jealous of.

I guess I'll just have to settle for less. Out of curiousity, how much $$$$ for something like that?

John, a system like that you'd be looking at $26,000 not including processing and amplifiers. To be fair, since it was a one-off project I really wanted to do, I think the actual price was closer to $12,000 for drivers, enclosures, delivery and installation. The client did much of the enclosure work themselves, once the plans and proto were built. Yes, I am THAT lazy!

My previous post only seems ridiculous, until you consider that at a mere $50 a week, a person could set aside for say, [4-5] nice little sealed subs like the SVS SB12+ a year. In a couple of years, you'd be up to EIGHT boxes, never see or hear the limiters, and have lovely distributed room placement options. Suddenly $5000 at a rate less than half the monthly payment of a subcompact car from Korea seems doable even if you eat at Taco Bell. Bet you could even get a discount!

:p

...edit...
My thinking has evolved to this point on subs. In order to make certain things start to really work in the bass-head's favor, we should be thinking in terms of PERCENT OF ROOM VOLUME MODULATION. The sad fact is, one 12", 15", 18" simply has near-zero coupling to the acoustic load of 15PSI air at frequencies below 40Hz or so.
...edit...
The solution? An assload of drivers! Instead of fighting at the edge of physics, take that same 1000Watt amp and run it into eight 12" drivers with more reasonable proportions of voice coil length, stupid big magnets, and nice rise and settling times in 0.5Qb - 0.707Qb. Let magnets do some of the work for you.
...edit...
:D

That's my POV as well. If you are not going to build a horn to act as the transformer between the driver and the atmosphere, your other option is to directly drive a surface equal to the mouth area of the horn.

I also think we're going to have to divide up the bass frequencies at say 25Hz so that driver solutions can be optimized, and to reduce intermodulation distortion.
This Elemental Designs video has folks in the ED thread oohing and aahing about extention -- it's the best visual depiction of how IM happens I've ever seen:
http://edesignaudio.com/edv2/13kv2_video.php

If you do not like what Marcy says report him.


Have you?

By the way, I glanced at your "HT" – is that the SVS HTITB with the upgraded sub?

Craig,

Keep up the great work,if some question your work...let them show by example and start a serious work and lets see how they do.Before their little fingers start to question your work.

I would ignore the plaintifs,unless they bring some positive info to the table that will help a good deal your testing,or the accuracy. So far from what I see(numbers)you are on target.

Negative people are best ...ignored.



LowOrder,

Agree with you,to get real slam,and negate the negative effects of room acoustics you use an apropriate amount of woofers/subs to pressurize the room. This goal I am very close in a 800cu ft space,using multiple capable subs(JL,Velo,Revel and company).In a 1000cu ft room I would say four f113 will start to do,for bass that is so palpable you will feel air be pushed in and out of your lungs. Who needs tactile transducers to shake a sofa when you have the real deal. ;)

My goal will be met this summer(I hope)when JL releases the GOTHAM,by then dual f112,dual f113 and a single GOTHAM should energise a space under 800cu ft the way I want.If not...another GOTHAM.Modesty not a chance,bring out the big gunns.

Ggunnell,

That was a funny video! You can actually see the surround start to deform, suggesting possible cavitation in an enclosure. The effect you are referring to is called Doppler Distortion, caused by the forward and back velocity of the cone frequency modulating a higher tone (thus IM). While I don't want to return to the good old days of accordion surrounds and 3mm of Xmax, I think a healthy Xmax of 6-12mm, and a very high "no" number >2 coupled with appropriate cumulative surface area (as you referred to a bass horn cross section) is a great formula. I've been sniffing around at the 16Ohm driver idea, as the turns-in-the-gap density leads to astounding Bl numbers. I find it hilarious that people are all ooh-ing and aah-ing at better than 80% efficient non-linear switching amps, while hooking them up to ever less efficient drivers because the magnetic field is stretched so thin over such an obnoxiously long winding. Remember, at a given impedance, a longer winding length means fewer turns in the field. The Lorentz Force is thus diminished.

Build a driver that sneaks up against its stops at 100W-200W, 16Ohms. Put it into a box spring that has a 0.5Qb. Provide reverse transfer function compensation EQ at minimum phase to an arbitrary low frequency f-3dB. Repeat...

Incidentally, some of my drivers have a Qts around 0.15. Even with a loose suspension and Fs around 20Hz, by the time you get into the 16Ohm range, you might be as low as Qts = 0.1; Vas to Vb ratio is then about 24 times! That is one tiny box.

:cool:

Regarding HSU, what does MK mean and what is difference between II and III. Thanks

sjmarcy, this is your FINAL warning.

Take a vacation from THIS thread or take a permanent vacation from AVS.
Your choice.

I will not allow you to continue de-railing this thread.

Kyser

PS - Guys, ignore this and get back on topic.

Thanks,

I also think we're going to have to divide up the bass frequencies at say 25Hz so that driver solutions can be optimized, and to reduce intermodulation distortion.
.

I like your suggestion and have tried it several times in a multi-sub setup by assigning different subs a narrow frequency range. One sub to 30hz, another 30hz- 60hz and still another to 60hz- 90hz for example. Nice cleaner sound with fewer audible artifacts. HSU's MSM is a step in that direction because it has effectively spliced the band and by doing so eased the demands on the sub amps.

Some people call compression the silent killer but I've always felt that IMD is the more neferious killer of sound quality and the more difficult one to measure in subwoofers. IMD subwoofer measurements that have been posted at other forums have been a valiant effort, but two closely spaced tones in the 60hz-70hz zone are going to create a mish mash of THD and modulation products which only very sophisticated equipment will be able to completely separate. Its funny to read the complements for inaccurate results derived faulty methodology. No surprise that some researchers seem to conclude that THD and IMD are so closely related to be almost one in the same. It doesn't work that way.

Agree with you,to get real slam,and negate the negative effects of room acoustics you use an apropriate amount of woofers/subs to pressurize the room. This goal I am very close in a 800cu ft space,using multiple capable subs(JL,Velo,Revel and company).In a 1000cu ft room I would say four f113 will start to do,for bass that is so palpable you will feel air be pushed in and out of your lungs. Who needs tactile transducers to shake a sofa when you have the real deal. ;)

My goal will be met this summer(I hope)when JL releases the GOTHAM,by then dual f112,dual f113 and a single GOTHAM should energise a space under 800cu ft the way I want.If not...another GOTHAM.Modesty not a chance,bring out the big gunns.

:eek: You know Ear, there are cheaper ways to build an atmospheric pressure chamber. ;)

Regarding HSU, what does MK mean and what is difference between II and III. Thanks

MK refers to the word, "Mark" as in, version (as far as I know. I could refer to Peter Marcks of Hsu, ahaha.

This info may help you to begin sorting out the differences:

http://forum.hsuresearch.com/showpost.php?p=20504&postcount=69

From this thread: http://forum.hsuresearch.com/showthread.php?t=2381

.

I like your suggestion and have tried it several times in a multi-sub setup by assigning different subs a narrow frequency range. One sub to 30hz, another 30hz- 60hz and still another to 60hz- 90hz for example. Nice cleaner sound with fewer audible artifacts. HSU's MSM is a step in that direction because it has effectively spliced the band and by doing so eased the demands on the sub amps.

Some people call compression the silent killer but I've always felt that IMD is the more neferious killer of sound quality and the more difficult one to measure in subwoofers. IMD subwoofer measurements that have been posted at other forums have been a valiant effort, but two closely spaced tones in the 60hz-70hz zone are going to create a mish mash of THD and modulation products which only very sophisticated equipment will be able to completely separate. Its funny to read the complements for inaccurate results derived faulty methodology. No surprise that some researchers seem to conclude that THD and IMD are so closely related to be almost one in the same. It doesn't work that way.

Maybe I'm coming out of left field here, and I apologize if it's been mentioned before - but maybe a form of IMD (intermodulation distortion) has something to do with the limiting effect on the PB-12NSD which has been discussed ad nauseum.

I'm wondering if that once the driver was pushed to it's limits in the deep bass range (~20hz), that besides having the amp begin limiting it also became impaired at reproducing some higher frequencies. Any chance of that?

Edit - Hmm...~23hz had the peak spl for the scene, ~46hz (2nd harmonic) had limiting...I wonder what ~69 (3rd harmonic) or ~92hz (4th harmonic) looked like....

Jon,

Its an interesting point you make, that as you run out of excursion, higher frequencies that are additive in phase with the crest of the fundamental are "pushed out" to the no-displacement-left zone. Bi-amplification has a similar effect on the headroom of power amplifiers. Bridging one of my Crown K2 amps at 2500W into 4Ohms and hooking it up to the sub PASSIVELY and running to similar output levels could confirm your theory. This would avoid any chance of amplifier clipping before the driver just commits suicide, as nearly any driver would.

:)

The Haunting DVD-DTS is on its way ... this should make for some more interesting graphs, especially with the waterfall chart handy.

Jon,

Its an interesting point you make, that as you run out of excursion, higher frequencies that are additive in phase with the crest of the fundamental are "pushed out" to the no-displacement-left zone. Bi-amplification has a similar effect on the headroom of power amplifiers. Bridging one of my Crown K2 amps at 2500W into 4Ohms and hooking it up to the sub PASSIVELY and running to similar output levels could confirm your theory. This would avoid any chance of amplifier clipping before the driver just commits suicide, as nearly any driver would.

:)

Well, what are you waiting for? :D

Haha, I don't actually own any products made by SVS, Craig does. I was suggesting a protocol to eliminate the amplifier variable.

As I'm under the conceit "I can do better" I only own subs that are a result of my own design work. Lets just say my menagerie would raise some eyebrows...

;)

Consider my eyebrows ready to be raised. Pics please.

I'm not ready to unveil my own madness. To reward your future patience, I will instead share someone else's efforts that will give a sense of scale of my own undertaking. I don't espouse this approach, architectural complications being but one of many objections. However, I've got to give Kudos hands down simply for the LEVEL OF COMMITMENT (pun intentional) shown by this guy...

http://www.royaldevice.com/custom.htm

:eek:

Try to ignore the crazy theories, most of which don't hold water in my opinion. In one crucial way, the SHEER SIZE of his subs, he hits it OUT OF THE PARK.

Craigsub,

Thanks for all the hard work in reviewing these subs. I, for one, really appreciate the effort.

Based partly on your reviews, I recently purchased a HSU VTF3.3 and I'm very happy. It really pressurizes the 14'x30' room nicely! Now I just have to figure out how to keep the pictures from falling off the walls! :)

Craig is welcome to exchange the PB12-NSD, but by all his subjective accounts, it is working fine.

Note, no where in this thread have I questioned Craig's objective data - I believe that graph is what TrueRTA spit out on that passage, and that is what Craig posted.

The real question to answer is what combination of variables resulted in this particular graph. It could very well be a combination of in-room FR, limiter activity, even the software itself. If I was present, we could try to duplicate the experiment and systematically eliminate/control variables and finger the culprit. Until such time all we can do is speculate - and we've seen that isn't terribly productive.

I might be able to break away for a day or two for Craig's next GTG, and I'll bring down my laptop and mic with various software programs and we can run some in-room and ground plane tests. Even then, Craig's reviews are more about in-room subjective and blind testing than they are about rigorous objective test data - and IMO we should focus more on the former and less on the latter.

Have you?

By the way, I glanced at your "HT" – is that the SVS HTITB with the upgraded sub?

I don't think I'd classify the SVS system as a Home Theater in a Box if that is what you were asking....lol

Yes it is the SBS bookshelves and the SCS Center paired with homemade surrounds for now and the SVS PB-12NSD.

I'll be looking hard at the MTS line to maybe replace the fronts and move the current fronts to surround sound duty...

I will add that the sound is VERY VERY impressive.....people that have gotten to hear a demo on it have been in awe of the sound....

Thats after coming from a Cerwin Vega system too...not just some cheap'o system...

Craig is welcome to exchange the PB12-NSD, but by all his subjective accounts, it is working fine.

Note, no where in this thread have I questioned Craig's objective data - I believe that graph is what TrueRTA spit out on that passage, and that is what Craig posted.

The real question to answer is what combination of variables resulted in this particular graph. It could very well be a combination of in-room FR, limiter activity, even the software itself. If I was present, we could try to duplicate the experiment and systematically eliminate/control variables and finger the culprit. Until such time all we can do is speculate - and we've seen that isn't terribly productive.

I might be able to break away for a day or two for Craig's next GTG, and I'll bring down my laptop and mic with various software programs and we can run some in-room and ground plane tests. Even then, Craig's reviews are more about in-room subjective and blind testing than they are about rigorous objective test data - and IMO we should focus more on the former and less on the latter.

What is puzzling to me is why this one graph caused such controversy. The "experiment" was nothing more than this: How much, in dB's, SPL @ 18-24 Hz could each subwoofer deliver during the Master-Commander opening battle scene before becoming audibly distressed ?

Linear response was not the issue - SPL in the deepest bass was. Nothing else was even being checked.

No matter what I threw at it, the PB12 would not do anything which sounded like audible distress. It is easily possible that the PB12 was receiving a signal which was 10-15 dB higher than the driver could have handled with the limiter out of the system.

When the lower output @ 45 Hz was pointed out, I re-ran the test with slightly lower DELIVERED #'s and we saw the "proper" response curve for this scene.

Guys ... I hope this does not come across as my being angry ... that is not the intent. But PLEASE ...can everyone who is mis-characterizing the first PB12-NSD graph ... would you PLEASE STOP ???

We have spent hours on this, and for some reason, certain people either cannot or will not read what actually happened, and understand it.

Ed ... You are right, the PB12 is functioning just fine.

I might be able to break away for a day or two for Craig's next GTG, and I'll bring down my laptop and mic with various software programs and we can run some in-room and ground plane tests. May I say that this is the most promising positive development in the ongoing disagreement that has lasted way too long, derailed all too many threads, caused much too much discomfort, and been detrimental to the sub community in general. I sincerely hope this comes to pass, and I hope I'm invited to that GTG, for I would really enjoy meeting you, Ed. Bravo!

May I say that this is the most promising positive development in the ongoing disagreement that has lasted way too long, derailed all too many threads, caused much too much discomfort, and been detrimental to the sub community in general. I sincerely hope this comes to pass, and I hope I'm invited to that GTG, for I would really enjoy meeting you, Ed. Bravo!


I agree, after all of my emails with Ed, and the postings on here with Ed and Craig I really hope I'm put on the list to attend this testing! :)

. Some people call compression the silent killer but I've always felt that IMD is the more neferious killer of sound quality and the more difficult one to measure in subwoofers. IMD subwoofer measurements that have been posted at other forums have been a valiant effort, but two closely spaced tones in the 60hz-70hz zone are going to create a mish mash of THD and modulation products which only very sophisticated equipment will be able to completely separate. Its funny to read the complements for inaccurate results derived faulty methodology. No surprise that some researchers seem to conclude that THD and IMD are so closely related to be almost one in the same. It doesn't work that way.

Rather than take this thread off-topic again, would you not be better to post such a comment in a new thread, preferably in a forum where the person it is clearly aimed at has the right of reply? If you have some valid critique of the methodology used, that would be the place to share it.

Actually it wasn't aimed at anyone and was a general response to a comment on IMD by ggunnel. However since then the gentleman in question and I have exchanged a few PMs. It would be a good discussion best saved for another day. ;)

I'm wondering if that once the driver was pushed to it's limits in the deep bass range (~20hz), that besides having the amp begin limiting it also became impaired at reproducing some higher frequencies. Any chance of that?



Jon,

Its an interesting point you make, that as you run out of excursion, higher frequencies that are additive in phase with the crest of the fundamental are "pushed out" to the no-displacement-left zone. Bi-amplification has a similar effect on the headroom of power amplifiers. Bridging one of my Crown K2 amps at 2500W into 4Ohms and hooking it up to the sub PASSIVELY and running to similar output levels could confirm your theory. This would avoid any chance of amplifier clipping before the driver just commits suicide, as nearly any driver would.

:)
What Jon beautifully zeroed into is what I was alluding to earlier. When pushed to it's limits, these things could happen, especially if the driver bottomed out. But apparently it had not yet bottomed out. It is very encouraging to know that Ed will try to make it for the next shootout. I will look forward for it.

I think all of this conversation should really get EVERYONE thinking about PROPER calibration of their subwoofers. EVEN if you like your subwoofer HOT, having it dialed in is CRITICAL!!! For proper sound, for proper frequency response if you have it calibrated properly we really will not be reaching the limits of our subwoofers.

Chances are IF you are reaching that LIMIT, than.....

A. Calibration might be an issue.

B.You need another Sub or a BIGGER more POWERFUL sub to fill your bass addiction.

C. Room size, bass traps, or something else might be playing a factor...


We will be pushing them within the ranges they are designed to be pushed, thus getting flat frequency response (obviously the room has a lot to do with that too). Craigs tests just go to show us what we can expect from our subs and the PB-12 graphs show that perfectly. A db or 2 TOO high can actually cause a little bit of a loss in some other areas, which makes PERFECT sense to me. When you looked at the PB-12 graph just before that limit was reached the reponse was in my opinion very very good.

The limiter talk should focus on the fact that this sub was TUNED to 18hz and that the electronics involved just help to make sure the ROOKIE or the VETERAN user doesn't push it past that limit to a damage point. Personally, I like that feature. If you want to avoid it, you move your way up into higher level subs anyways...

In conclusion, Calibration is KEY before anyone starts to talk about their subs performance. :)

ps......7-14 inches of snow for us today and tonight in Cleveland.....Craig how's the weather up there in Erie??? (My friends that live in Erie say they got DUMPED on hard in recent days)

What is puzzling to me is why this one graph caused such controversy...
You're not alone there! :rolleyes:

...I re-ran the test with slightly lower DELIVERED #'s and we saw the "proper" response curve for this scene...
Which should have put the whole issue to rest, except for enlightened comments like bgillyjcu's about how to benefit from this kind of information.

Unfortunately, a few people seemed to become ego involved, choosing to make this either a vindication or an assault on their brand preference. It was neither, just an observation to be used as one more information resource, nothing more.

Anyway, thanks for your efforts, craigsub. Like many others, I appreciate the information you have been willing to share, even if I reserve the right to (privately) disagree with some of your conclusions. ;)

By the way, while it couldn't be as much fun as testing the higher end subs, if you ever have the time, there are a lot of people here who would benefit from your evaluations of a couple more of the "entry level" subs, such as the STF-1 and BIC H-100 to compare with the X-Sub.

Craig, a while back, (in what I thought was lull in the action at your home:) ), about ranking the subs on music reproduction (>25Hz performance) alone. The >25Hz is not my invention as you know, just a result of the frequency output of musical instruments. Synthesizer, organ, very large drums, cannons, and the like have always been treated separately due to both their relative scarcity in music recordings (including movie soundtracks) and the physics involved in reproducing <25Hz levels.

The current AV123 sale on UFW-12's got me reviewing their forum where I came across this 3 page thread from almost exactly a year ago:
http://av123forum.com/showthread.php?s=&threadid=12379&perpage=15&highlight=ufw12&pagenumber=1
On page 2 you note that the UFW-12 equals the DD-18 in articulation over 30 Hz.

I remember in your review of the Maestro you commented that it's transient response matched the UFW-10's.

Who would care about such a ranking?
1. Folks who are strictly after >25Hz music reproduction
2. People who have small woofer main speakers (minimonitors) who are looking for a larger woofer and need a musical match with ther monitors first and extension below 25Hz second
3. People on a budget who are willing to sacrifice output below 25Hz for quality above it.
4. People going to a "high sub / low sub" system.

Anyway, I appreciate your 'broad shoulders' attitude and apologize for my own off-topic posts recently -- some of LowOrder's comments struck a chord :)

Craig, a while back, (in what I thought was lull in the action at your home:) ), about ranking the subs on music reproduction (>25Hz performance) alone. The >25Hz is not my invention as you know, just a result of the frequency output of musical instruments. Synthesizer, organ, very large drums, cannons, and the like have always been treated separately due to both their relative scarcity in music recordings (including movie soundtracks) and the physics involved in reproducing <25Hz levels.

The current AV123 sale on UFW-12's got me reviewing their forum where I came across this 3 page thread from almost exactly a year ago:
http://av123forum.com/showthread.php?s=&threadid=12379&perpage=15&highlight=ufw12&pagenumber=1
On page 2 you note that the UFW-12 equals the DD-18 in articulation over 30 Hz.

I remember in your review of the Maestro you commented that it's transient response matched the UFW-10's.

Who would care about such a ranking?
1. Folks who are strictly after >25Hz music reproduction
2. People who have small woofer main speakers (minimonitors) who are looking for a larger woofer and need a musical match with ther monitors first and extension below 25Hz second
3. People on a budget who are willing to sacrifice output below 25Hz for quality above it.
4. People going to a "high sub / low sub" system.

Anyway, I appreciate your 'broad shoulders' attitude and apologize for my own off-topic posts recently -- some of LowOrder's comments struck a chord :)

Thanks for bringing this up again - I have been putting a lot of thought into this, because the listening tests (mine and others) have shown some of the subs doing a great job on music only tracks.

The UFW-12 is almost the perfect example of a subwoofer which is outstanding on music, but gets a lower score due to its movie spectacular ... relative weakness.

The absolute top contenders do everything well ... the Fathoms, Velodyne and Maestro XL are all stellar performers above 25 Hz. The Hsu products also do very well. The PB12-Ultra is another excellent music performer ... while the Plus and NSD products lean towards better choices where HT takes precedence over music.

I will see how to put the music performance into perspective from all the notes taken here ... and will try to get something up this weekend.

Keep in mind that even within the same manufacturer, people disagree about SQ in the subs. Buckeyefan thought the PB12-Plus/2 was the sonic equal to the Ultra, in terms of music/sound quality. I find the Ultra to be a more articulate reproducer of music than the Plus/2.

Back to an earlier thought ... Ed is, of course, welcome here, as always. Could make for an interesting GTG .... with lots of attendees.

Thanks for bringing this up again - I have been putting a lot of thought into this, because the listening tests (mine and others) have shown some of the subs doing a great job on music only tracks.

The UFW-12 is almost the perfect example of a subwoofer which is outstanding on music, but gets a lower score due to its movie spectacular ... relative weakness.

The absolute top contenders do everything well ... the Fathoms, Velodyne and Maestro XL are all stellar performers above 25 Hz. The Hsu products also do very well. The PB12-Ultra is another excellent music performer ... while the Plus and NSD products lean towards better choices where HT takes precedence over music.

I will see how to put the music performance into perspective from all the notes taken here ... and will try to get something up this weekend.

Keep in mind that even within the same manufacturer, people disagree about SQ in the subs. Buckeyefan thought the PB12-Plus/2 was the sonic equal to the Ultra, in terms of music/sound quality. I find the Ultra to be a more articulate reproducer of music than the Plus/2.

Back to an earlier thought ... Ed is, of course, welcome here, as always. Could make for an interesting GTG .... with lots of attendees.
Craig,
Assigning points (a number) to a subwoofer is an extremely hard problem and I am glad you are addressing it. I haven't evaluated how you are calculating the numbers (mean, geo mean, weighted average, etc) but regardless, it is extremely difficult assigning a single number to a sub and then trying to make sense out of it. That is also in many ways contributing to all the tension here. So here is a suggestion. Rather than a single number, why not have multiple numbers (maybe a 5-tuple), each representing a certain quality of the sub? Again ranking it on Music and Movies may not be the best approach. I have thought about this long and hard and it is very difficult to rank something that way because there is a lot of overlap between music and movies (movies have music and effects).
Just a thought and I hope it helps.
Regards,
-Jai

Good idea.

Some ideas:

Movie/HT Performance:
Music Performance:
Extension:
Mid-bass:
Articulation:
Max SPL:
Looks/Finish:
Integration (Ease of):

Richard Hardesty used to have a rating system like that when he reviewed subwoofers for WSR. I can't remember the categories, but I think there were 5 or 6. With 5 stars being the best in each case. He used increments of .5 I believe, which is basically a rating scale of 1-10. I'll have to look at the special subwoofer review edition he did for WSR in 2000, and see exactly what categories he used. Funny, I guess they used to call him "Dr. Boom". :D
Btw, he was more known for his subjective tests as well. I know he used some type of SPL meter to measure max. SPL, but he used his "ear" more than anything else to define the attributes of a particular subwoofer. For example he would state when he heard "audible" distortion. I don't think he ever measured for THD or compression, etc. Could be wrong though.

The way that everyone seems to argue about the Def. Tech. specs it would seem like a good idea to test the Trinity, Reference or Supercube I to finally see where these subs actually stand in the rankings.

Movie/HT Performance:
Music Performance:
Extension:
Mid-bass:
Articulation:
Max SPL:
Looks/Finish:
Integration (Ease of):

Great suggestions. Here are some in my mind, some measurable and some subjective. Of course there would be overlaps in which case, finding the least common denominator representative would be needed and this can be fine tuned after some iterations.

Realism
Musicality
Attack/Decay
Tactile movement
Shake value

dBSPL Max
Max extension (depending on SPL at say 16 and 12 Hz)

...t is extremely difficult assigning a single number to a sub and then trying to make sense out of it. That is also in many ways contributing to all the tension here. So here is a suggestion. Rather than a single number, why not have multiple numbers (maybe a 5-tuple), each representing a certain quality of the sub...
I'd vote for this, too. Not necessarily eliminating the single numbers, but additionally publishing the individual scores that went into it. Everyone has his own weighting values, and this would permit readers to evaluate according to the elements most important to them.

Hopefully, this wouldn't be more work for you since you probably already do something like this in the process of establishing your ratings.

Good idea.

Some ideas:

1... Movie/HT Performance:
2... Music Performance:
3... Extension:
Mid-bass:
4... Articulation:
5... Max SPL:
Looks/Finish:
Integration (Ease of):

We used #'s 1 through 5 to evaluate each sub ... then used the overall points system as the each 3 points = 15% improvement.

The original subwoofer to get a 100 was the DD-18. 100 did not mean a perfect score, but rather that it was the standard, having "won" its test with the Maestro XL.

The Maestro scored 87 points ... thus the DD-18 was 15%, or 3 points higher than the Maestro XL.

The Tyke sub ... the little one from AV123, scored a total of 13 points.

In this scale, with 20 being the standard, 10 meant half the performance of 20, and 5 half the performance of 10.

The Tyke (from memory) scored as follows

Home Theater - 2 points
Music - 3 points
Extension - 3 points
Articulation - 3 points
Max SPL - 2 points

We do have notes for all the subs ... but you are looking at a LONG post to put everything here.

We used #'s 1 through 5 to evaluate each sub ... then used the overall points system as the each 3 points = 15% improvement.

The original subwoofer to get a 100 was the DD-18. 100 did not mean a perfect score, but rather that it was the standard, having "won" its test with the Maestro XL.

The Maestro scored 87 points ... thus the DD-18 was 15%, or 3 points higher than the Maestro XL.

The Tyke sub ... the little one from AV123, scored a total of 13 points.

In this scale, with 20 being the standard, 10 meant half the performance of 20, and 5 half the performance of 10.

The Tyke (from memory) scored as follows

Home Theater - 2 points
Music - 3 points
Extension - 3 points
Articulation - 3 points
Max SPL - 2 points

We do have notes for all the subs ... but you are looking at a LONG post to put everything here.
Thanks for the explanation. So it assumes equal weights for each parameter. Though not incorrect, it gives fewer degrees of freedom. Once you establish the order of the 5-tuple, example, (HT, Music, Ext, Art, Max), then instead of one point, you can display it as (2, 3, 3, 3, 2).
Now each person may apply different weights and then see what is right for them.

Thanks for the explanation. So it assumes equal weights for each parameter. Though not incorrect, it gives fewer degrees of freedom. Once you establish the order of the 5-tuple, example, (HT, Music, Ext, Art, Max), then instead of one point, you can display it as (2, 3, 3, 3, 2).
Now each person may apply different weights and then see what is right for them.

Exactly .. and there are still overlapping characteristics from each unit. For example: The Tyke could probably score much higher in articulation, except it cannot do so at any reasonable volume. Stick it 2 feet from you, and it is a pretty decent little sub ... but place it in a normal room, under real world circumstances, and it is not going to do so well.

The SensibleSound review for the VTF3mk3 is available at the HSU website now. http://hsuresearch.com/products/VTF_3MK3SensibleSoundReviewJanFeb2007.pdf

...We do have notes for all the subs ... but you are looking at a LONG post to put everything here.
A spreadsheet, perhaps?

I think all of this conversation should really get EVERYONE thinking about PROPER calibration of their subwoofers. EVEN if you like your subwoofer HOT, having it dialed in is CRITICAL!!! For proper sound, for proper frequency response if you have it calibrated properly we really will not be reaching the limits of our subwoofers.

Chances are IF you are reaching that LIMIT, than.....

A. Calibration might be an issue.

B.You need another Sub or a BIGGER more POWERFUL sub to fill your bass addiction.

C. Room size, bass traps, or something else might be playing a factor...



The other issue may be placement, bgillyjcu.

The big thing that I keep running into has to do with owner's expectations. If you purchase a HSU VTF-2 or a SVS PB10-NSD, don't expect it to perform like a turbo or a Plus 2. They are designed to work within a specified low end frequency extension, and a specific size of space. You put them in a 3500^3 of space, and they are likely to fall short. And remember that you are always working within the framework of a trade.... you are compromising on either cabinet size, SPL, or low end extension. And then a savvy manufacturer is likely to put some limiters on their systems so that the user does not exceed the fundamental specifications engineered into the product by purpose or by accident and damage it.


We will be pushing them within the ranges they are designed to be pushed, thus getting flat frequency response (obviously the room has a lot to do with that too). Craigs tests just go to show us what we can expect from our subs and the PB-12 graphs show that perfectly. A db or 2 TOO high can actually cause a little bit of a loss in some other areas, which makes PERFECT sense to me. When you looked at the PB-12 graph just before that limit was reached the reponse was in my opinion very very good.

The limiter talk should focus on the fact that this sub was TUNED to 18hz and that the electronics involved just help to make sure the ROOKIE or the VETERAN user doesn't push it past that limit to a damage point. Personally, I like that feature. If you want to avoid it, you move your way up into higher level subs anyways...

:)

In other words, the sub performed as it was engineered to do, and then safety features were incorporated to ensure that the sub's capabilities were not exceeded.

ps......7-14 inches of snow for us today and tonight in Cleveland.....Craig how's the weather up there in Erie??? (My friends that live in Erie say they got DUMPED on hard in recent days)

Man... I miss being back home.... It's been relatively dry in the Treasure Valley....

Good idea.

Some ideas:

Movie/HT Performance:
Music Performance:
Extension:
Mid-bass:
Articulation:
Max SPL:
Looks/Finish:
Integration (Ease of):

Also consider:

Bang for the Buck


Splotto

Craig,
I have a VTF-2 Mk I (with the 160 watt amp) and am thinking of upgrading to a VTF-2 Mk III and possibly the MBM-12. My satellites roll of at about 100 hz. I have not seen the upper frequency response of the VTF-2 Mk III. Did you measure it? HSU's website use to list the response, for example, as 25-120 hz +-1 db, but I can no longer find this information.

Have you had a chance to test the MBM-12 with the VTF-2.3 yet? If so, what are your impressions. Thanks.

JL Audio Fathom 113: 103 points
Velodyne DD-18: 100 points
ACI Maestro: 97 points
JL Audio Fathom 112: 95 points
Hsu VTF-3 HO + Turbo: 94 points
Hsu VTF-3 HO w/o Turbo: 92 points
Hsu VTF-3 Mark III + Turbo: 92 points
Hsu VTF-3 Mark III w/o Turbo: 91 points
SVS PB12-Ultra: 90 points
Axiom EP-500: 90 points
Hsu VTF-2 Mark III + Turbo: 88 points
SVS PB12-Plus/2: 87 points
SVS PB12-NSD: 86 points
Hsu VTF-2 Mark III w/o Turbo: 86 points
Rocket UFW-12: 85 points (provisional)
SVS PB10-NSD: 83 points
Rocket X-Sub: 78 points
Rocket Tyke: 60 points

Craig,
If possible and not too much trouble, it would be great if you can post the (HT, Music, Ext, Art, Max) values for these subs.
Thanks,
-Jai

Craig is welcome to exchange the PB12-NSD, but by all his subjective accounts, it is working fine.

Note, no where in this thread have I questioned Craig's objective data - I believe that graph is what TrueRTA spit out on that passage, and that is what Craig posted.

The real question to answer is what combination of variables resulted in this particular graph. It could very well be a combination of in-room FR, limiter activity, even the software itself. If I was present, we could try to duplicate the experiment and systematically eliminate/control variables and finger the culprit. Until such time all we can do is speculate - and we've seen that isn't terribly productive.

I might be able to break away for a day or two for Craig's next GTG, and I'll bring down my laptop and mic with various software programs and we can run some in-room and ground plane tests. Even then, Craig's reviews are more about in-room subjective and blind testing than they are about rigorous objective test data - and IMO we should focus more on the former and less on the latter.

Great post Ed, and as someone who still currently owns both SVS and HSU products, I appreciate your objective attitude and factual contributiuons to this thread.

Perhaps a numerical score for music performance is too difficult, Craig -- but if you could even list them in your preceived order for "low end of piano and up" music it would help. As you say there may be disagreement and discussion on an exact ranking in any case.

The way I would do it would be on tone quality only, and then use the posted experiences of everyone to determine relative SPL. For instance, the general conclusion is that one UFW-12 is slightly louder than two UFW-10's -- rather than try to assign an SPL point system of 1 to the UFW-10 and 2 to the UFW-12, I'd just accumulate statements like "one UFW-12 is slightly louder than two UFW-10's" and leave it at that.

Else you will be defending point assignments for pitch definition ad infinitum :)

We used #'s 1 through 5 to evaluate each sub ... then used the overall points system as the each 3 points = 15% improvement.

The original subwoofer to get a 100 was the DD-18. 100 did not mean a perfect score, but rather that it was the standard, having "won" its test with the Maestro XL.

The Maestro scored 87 points ... thus the DD-18 was 15%, or 3 points higher than the Maestro XL.

The Tyke sub ... the little one from AV123, scored a total of 13 points.

In this scale, with 20 being the standard, 10 meant half the performance of 20, and 5 half the performance of 10.

The Tyke (from memory) scored as follows

Home Theater - 2 points
Music - 3 points
Extension - 3 points
Articulation - 3 points
Max SPL - 2 points

We do have notes for all the subs ... but you are looking at a LONG post to put everything here.

For the next get together, my suggestions for a multi-dimensional score is as follows. I will start with the measurable ones.

1. Max SPL - Dolby reference level for the LFE channel is 115dB peaks at the listening position. A sub that delivers 115dB gets 1 point. A sub that delivers 125dB (twice as loud gets 2 points). A sub that delivers only 95dB gets -1 points and so on. Seeing this would readily help someone decide that a sub that has negative points is performing below dolby reference levels. Anything above a 1 sure would make a person grin with joy :D


2. Shake value or SV (this can encompass extension and tactile movement too) - Similar to what Brian Florian used in his article (small bug there with the shake values) is very intuitive. At 20Hz 70dB would be a 1, 80dB which is twice as loud is a 2 and so on. Some subs are natively tuned for 20Hz, some 16Hz and some even 12Hz. So to do justice to the subs with greater extension, it would be nice to have 3 orders for the shake value. SV (1st order) is for 20Hz, SV (2nd order) is for 16Hz and SV (3rd order) is for 12Hz). A sub that delivers 110dB at 20Hz, 100dB at 16Hz and 90dB at 12Hz would have the values 4, 3 and 2 for SV 1st, 2nd and 3rd order respectively. A sub that earns 4, 0, 0 has a steep roll off. A sub like the submersive would have a smoother roll-off etc.
I know these may be difficult first, but as people get used to it, it will become more and more intuitive.


Now for the more difficult subjective ones. I would avoid giving points for HT and Music as 2 separate parameters. Instead, I would go for

3. Musicality - How beautiful do people think the music sounds on a scale of 5. It could be music or in movies.

4. Realisim - How real do people think it is. Does it sound like a real helicopter, engine sounds, rain, thunder, lightening, piano sounds, percussion, pipe organ etc also on a scale of 5.

5. Attack and Decay - Though subjective, people pick this up very quickly. The question of how fast always comes up.


Any thoughts?
Thanks,
-Jai

The 1st, 2nd and 3rd order SV can simply be added to get a single SV if a simplification is needed. It would still convey the message on how good the extension is and how much it will rock your boat.
-Jai

The SensibleSound review for the VTF3mk3 is available at the HSU website now. http://hsuresearch.com/products/VTF...wJanFeb2007.pdf

Just read it...wow! :eek:

Just read it...wow! :eek:

Great review.

I would like to hear anyones comments on the wiring comments made by the rviewer.

Being a n00b when it comes to subs, speakers and receivers I was confused about the reviewers suggestions on how to wire your sub and speakers.

Thanks,
Splotto

Any thoughts on what I posted folks?
Yeah, great review on the VTF3MK3, but wouldn't you all like to contribute to the next amazing shootout that craig's gonna do for us?!! Especially with Ed out there, this is going to be special and I can't wait. Craig, keep up the amazing work!
Thanks,
-Jai

I wonder how would compare the HO to the VTF3MK3 in Craigsub shootout!

A simpler idea ... Gents, IF we can put this GTG together, especially with the arrival of the new Ultra and the MFW-15 + BMF from AV123, it will be a pretty cool event.

As for the ratings ... Rather than overcomplicate things (thinking of the less experienced subwoofer user here), an idea:

We give a tally for the Music and HT performance levels from the 100 points.

For example ... The Fathom gets 53 for HT and 50 for Music.

Then we add ... Extension ... the point to which each sub can hit, in room, with relatively little compromise...

The Fathom 113 now looks like this:

Fathom 113 ... 103 Points - 53 HT - 50 M - 15Hz Ext.
Velodyne DD-18 ... 100 Points - 50 HT - 50 M - 15Hz Ext

I am trying to keep this a relatively simple task while providing more info ... :)

>I am trying to keep this a relatively simple task while providing more info ...

I think craigsub's idea is a great compromise and will lead to very useful comparisons for readers with differing needs.

A simpler idea ... Gents, IF we can put this GTG together, especially with the arrival of the new Ultra and the MFW-15 + BMF from AV123, it will be a pretty cool event.

As for the ratings ... Rather than overcomplicate things (thinking of the less experienced subwoofer user here), an idea:

We give a tally for the Music and HT performance levels from the 100 points.

For example ... The Fathom gets 53 for HT and 50 for Music.

Then we add ... Extension ... the point to which each sub can hit, in room, with relatively little compromise...

The Fathom 113 now looks like this:

Fathom 113 ... 103 Points - 53 HT - 50 M - 15Hz Ext.
Velodyne DD-18 ... 100 Points - 50 HT - 50 M - 15Hz Ext

I am trying to keep this a relatively simple task while providing more info ... :)


Great Idea....a simple breakdown that yields more information for the 'average' subwoofer reader. Everyone can identify the subs based on HT or Music...and figure in the extension factor. Personally I like this becaue I'm MOST interested in the HT aspect. So those are really the numbers I'm most interested in. :cool:

>I am trying to keep this a relatively simple task while providing more info ...

I think craigsub's idea is a great compromise and will lead to very useful comparisons for readers with differing needs.

Works for me.

The SensibleSound review for the VTF3mk3 is available at the HSU website now. http://hsuresearch.com/products/VTF_3MK3SensibleSoundReviewJanFeb2007.pdf

think he liked it? ;)

A simpler idea ... Gents, IF we can put this GTG together, especially with the arrival of the new Ultra and the MFW-15 + BMF from AV123, it will be a pretty cool event.

As for the ratings ... Rather than overcomplicate things (thinking of the less experienced subwoofer user here), an idea:

We give a tally for the Music and HT performance levels from the 100 points.

For example ... The Fathom gets 53 for HT and 50 for Music.

Then we add ... Extension ... the point to which each sub can hit, in room, with relatively little compromise...

The Fathom 113 now looks like this:

Fathom 113 ... 103 Points - 53 HT - 50 M - 15Hz Ext.
Velodyne DD-18 ... 100 Points - 50 HT - 50 M - 15Hz Ext

I am trying to keep this a relatively simple task while providing more info ... :)

I think that would be the best compromise. For me and others that are more interested in using our subs for mostly HT it gives all the info we need.

One question, using the HO w/out turbo for example, would you differentiate between the 16Hz and 22Hz tune or just give the number based on one of them?

Good idea, Craig! :)

A simpler idea ... Gents, IF we can put this GTG together, especially with the arrival of the new Ultra and the MFW-15 + BMF from AV123, it will be a pretty cool event.

As for the ratings ... Rather than overcomplicate things (thinking of the less experienced subwoofer user here), an idea:

We give a tally for the Music and HT performance levels from the 100 points.

For example ... The Fathom gets 53 for HT and 50 for Music.

Then we add ... Extension ... the point to which each sub can hit, in room, with relatively little compromise...

The Fathom 113 now looks like this:

Fathom 113 ... 103 Points - 53 HT - 50 M - 15Hz Ext.
Velodyne DD-18 ... 100 Points - 50 HT - 50 M - 15Hz Ext

I am trying to keep this a relatively simple task while providing more info ... :)
Craig,
That's better, still does not do justice to your great effort IMHO. A lot of users here are above average serious users. An average casual user honestly may not be able to tell the difference between a DD18 and a Plus/2, so my hope is that your points would cover a wider audience including folks who are into professional audio. Not everyone takes the time, effort and money needed to do what you do. You fund yourself and no one supports you financially to do this. So you hold a unique position here and hence my requests. Please do give a lot more thought into what I had suggested earlier. Really, I don't think it is over complicated. At first it can be intimidating, I agree, but people will get used to it very quickly. I am not saying, go with exactly what I suggested. I am suggesting raising the bar in the way points are posted. If THD, group delay, impulse response, etc etc are brought into the equation, I can see how quickly it would turn off the average user. So that is not what I suggest.
I hope my request will be considered.
-Jai

Craig,
You fund yourself and no one supports you financially to do this.
-Jai


I think thats why if we have a GTG that we should all bring the beer and chips :D

I'll bring some Gunniess and Doritos!!! :cool:

...Rather than overcomplicate things ... We give a tally for the Music and HT performance levels from the 100 points... Then we add ... Extension ...

...I am trying to keep this a relatively simple task while providing more info ... :)
That looks great and would be truly helpful.

I'd love to see a 25-50 Hz band max SPL reading, too, (or something similar) which would add a key piece of objective basic information without complicating the ratings too much. But not at the cost of making your task more difficult.

I'm just going to chime in here on the DD-18 and JL113 comparison having spent quite a bit of time now with each sub. Like many people here I have alot of time for Craig and his views but different users will have different perceptions. Much like the last GTG where everyone had slightly different rankings.

I've listened to both subs for music and HT and it is just about indistinguishable between these cost- no- object subs. The recent Audioholics review quite rightly ranked the DD-18 as the finest sub they have ever reviewed and tested. Most of the tests were conducted at the 100ft testing pole in Dwight just before my visit there last fall and the views of all were unamimous that the 4pi test results were simply outstanding in all respects. The CEA 2010 subwoofer measurement guidelines make mention of a reference sealed sub and I would not be surprised if its the DD-18, but thats just specualtion on my part.

The DD-18 like the JL113 is about as good a subwoofer as you can find today. In fact from my perspective the 4pi tests disclosed, show arguably better results than the numbers released by JL. However in real world listening I'm not sure it matters much since they do have very similar sonic qualities. Where the JL has an advantage is on size and price but its single shot ARO is no match for the much superior digital SMS equalizer in the DD-18. The JL will not be as linear in room as the DD-18 but even with that factored in its sound quality is exceptional.

It really is too close to call so I rank them equally, and IMO does point to a problem with these simple numerical weightings. The 8 criteria used by Audioholics below are more meaningful and as you can see their views on the DD-18 align with mine. I appreciate and respect Craigs views but as can be seen by the number of people obsessing with a sub's number, I'm not sure it does justice to the sub or the reader. Especially when so many subs are separated by one or two points. In the absence of a better numerical weighting system I think the straight ranking is more meaningful and more representative of the Craigs subjective assessment. In that regard when people have asked me I have suggested not putting much weight on the numerical weighting but to look to the rank as being much more indicative. Keep up the great work Craig and I'll take you up on your offer for the next GTG. :)

By the way after going back and forth between these two great performers I just took delivery of a slightly used DD-18 so price wasn't a factor. The digital electronics in the Velo was my tipping point.


http://www.audioholics.com/productreviews/loudspeakers/VelodyneDD18p4.php

...as can be seen by the number of people obsessing with a sub's number, I'm not sure it does justice to the sub or the reader.

nice write-up john, and a great point that should be kept in mind.

A simpler idea ... Gents, IF we can put this GTG together, especially with the arrival of the new Ultra and the MFW-15 + BMF from AV123, it will be a pretty cool event.

Craig,
Approximately when are you planning on putting the next GTG together?
It would be great if you can include the Submersive1 and also the Danley DTS-20.
Thanks,
-Jai

Originally Posted by jakeman
...as can be seen by the number of people obsessing with a sub's number, I'm not sure it does justice to the sub or the reader.
I share this concern, which is the reason I'm hoping to see a few qualifiers such as those craigsub has proposed. There is nothing "wrong" about his current rating system, per se, but the single number system seems to lead some readers to conclude that one sub is "better" than the next when it may not be for their requirements.

As usual, Jakeman represents a voice of reason. Having just sold my "slightly used" DD-18 and installed dual F113's, I can say that overall, the dual (non co-located) Fathoms do a better job distributing bass energy and sound in my less than ideal space. I agree with John's point regarding the Velo PEQ vs the Fathom ARO. I have a rather nasty 10db peak at 60Hz at one of my listening positions that is likely due to room dimensions. Fortunately, this is where the SO sits so is not a big deal :p . The JL folks have been very helpful with this and have given me some things to try to help resolve the peak, but it may end up that I just purchase an SMS-1 and go at it that way (anyone have one to sell?).

Re Craig's tests, I have no problem with his rankings nor system of weighting. For me, a subs performance and my ultimate satisfaction with it is based upon subjective listening. I like the fact that Craig's test include numbers and subjective opinion. We are all responsible for filtering/evaluating the data we receive ... for me, the more the better.

I'm just going to chime in here on the DD-18 and JL113 comparison having spent quite a bit of time now with each sub. Like many people here I have alot of time for Craig and his views but different users will have different perceptions. Much like the last GTG where everyone had slightly different rankings.

I've listened to both subs for music and HT and it is just about indistinguishable between these cost- no- object subs. The recent Audioholics review quite rightly ranked the DD-18 as the finest sub they have ever reviewed and tested. Most of the tests were conducted at the 100ft testing pole in Dwight just before my visit there last fall and the views of all were unamimous that the 4pi test results were simply outstanding in all respects. The CEA 2010 subwoofer measurement guidelines make mention of a reference sealed sub and I would not be surprised if its the DD-18, but thats just specualtion on my part.

The DD-18 like the JL113 is about as good a subwoofer as you can find today. In fact from my perspective the 4pi tests disclosed, show arguably better results than the numbers released by JL. However in real world listening I'm not sure it matters much since they do have very similar sonic qualities. Where the JL has an advantage is on size and price but its single shot ARO is no match for the much superior digital SMS equalizer in the DD-18. The JL will not be as linear in room as the DD-18 but even with that factored in its sound quality is exceptional.

It really is too close to call so I rank them equally, and IMO does point to a problem with these simple numerical weightings. The 8 criteria used by Audioholics below are more meaningful and as you can see their views on the DD-18 align with mine. I appreciate and respect Craigs views but as can be seen by the number of people obsessing with a sub's number, I'm not sure it does justice to the sub or the reader. Especially when so many subs are separated by one or two points. In the absence of a better numerical weighting system I think the straight ranking is more meaningful and more representative of the Craigs subjective assessment. In that regard when people have asked me I have suggested not putting much weight on the numerical weighting but to look to the rank as being much more indicative. Keep up the great work Craig and I'll take you up on your offer for the next GTG. :)

By the way after going back and forth between these two great performers I just took delivery of a slightly used DD-18 so price wasn't a factor. The digital electronics in the Velo was my tipping point.


http://www.audioholics.com/productreviews/loudspeakers/VelodyneDD18p4.php

Do you guys think a letter grade would help instead...ex. A+, A, A-, etc. Obviously several subwoofers can occupy an A+ rating...

I share this concern, which is the reason I'm hoping to see a few qualifiers such as those craigsub has proposed. There is nothing "wrong" about his current rating system, per se, but the single number system seems to lead some readers to conclude that one sub is "better" than the next when it may not be for their requirements.
I more or less share this sentiment, which is why I brought up Richard Hardesity's rating system, or some variant. What Craig is doing here is amazing, a few qualifiers may help out in delinating each subs strong and weak points.

With that said I found that issue of WSR called "The Essential Subwoofer Buyer's Guide" (Over 50 subs reviewed).
Here is his Subjective list of categories tested for:

1) Overall Music Reproduction
2) Overall Effects Reproduction
3) Impact
4) Tonal Defintion
5) Freedom from Overhang
6) Rhythm and Pace (ability to follow the rhythm and pace of a musical selection)
7) Midrange coloration
8) Box Integrity (freedom from audible enclosure resonance, using sine wave)
9) Distress (can the sub be easily overdriven)
10) Subjective deep bass (probably want to change to actual measured response)
11) ability to reach 105dB@35Hz (at the LP, which in R.H. case was 3 meters)
12) Ability to play at 25Hz without subsantial reduction in SPL

Of course some of these can be combined, like rhythm and pace, and tonal definition into Overall music reproduction. And like I eluded to in # 10, instead of subjective deep bass, just actually measure how low it can go and at what SPL. Number 11, where it states the ability to reach 105dB@35Hz may want to raised to todays standards (this review was done in 2000) to something like the abilty to hit 110dB@30Hz or something. And maybe number 12 goes down to 20Hz instead of 25Hz. Other things like Midrange coloration and Box integrity could easily be excluded to lessen the chore. :)

With that said he used a rating scale of 1-5 for each category (in .5 increments). 5 being excellent, 4 being good, 3 meaning just average, 2 meaning poor, and 1 unacceptable.

Anyway, something like this system would help people pin-point particular strength and weakenesses that are important to them in a given sub. Of course 5's across the board is ideal, but that is where you have to "pony up" the money for a f113 or a DD-18. There are always compromizes that have to be made when people have consider their budgets though. ;)

Wow ... TONS of info here .... great job all (please see my post for my limited choices); however, because i am too lazy to read through ALL of this, and am primarily interested in musical subs that are quick, AND on a limited budget, can ANYONE use this rating system to re-rank this list to one that takes into consideration cost??? I.E. best ranking vs. cost scores. Anyone?? Mr. Craig?? :o

With that said I found that issue of WSR called "The Essential Subwoofer Buyer's Guide" (Over 50 subs reviewed).


Great nickname "MusicFirst". Interesting you keep mentioning Hardesty and that long article he wrote in the winter, 2000 . To this day, it has remained in a stack of audio magazines on a coffee table in my 2 channel room. It's still the seminal reference article on subwoofers and his 30 pages of "Presenting The Fundamentals Parts One-Five" are required reading for anyone wanting to understand the nuances. Even though I've read it a dozen times, there's always something in there which clarifies an issue I'm mulling over.

There's one paragraph in his intoduction which still rings true and which makes comparisons like this one difficult. Keep in mind his frequency limits were from subs 7 years ago and wouldn't always apply today.

Home theatre enthusiasts want subwoofers that play very loudly at high levels. They are generally satisfied by products with low frequency limits of 25hz-30hz. Music listeners may prefer to trade some of this high output for improved transient response and extended low frequency performance. Subwoofers that play the loudest seldom sound the best when reproducing music...

Unfortunately to get the best of both attributes still requires a big expenditure. Lower priced subs are usually tilted one way or the other despite most manufactuers claims that their products perform well for both HT and music.

... it has remained in a stack of audio magazines on a coffee table in my 2 channel room.
You know you're a geek when you've replaced "Den", "Living Room", "Library", etc., with nomenclatures referring to the room's audio capabilities. ;)

As usual Darin, now that you mention it, you're right. It's actually in our great room which has cathedral like acoustics. You must have been talking to my teenagers. :o :)

Some items to take into consideration ...

1. Cost was not an issue nor a factor when the "number" was assigned.

2. Built in EQ was not an issue for any sub, as this can be purchased separately.

3. All subs rated 75 points and higher are recommended for both music and theater use. All these subs have some strengths and weaknesses to consider. For a smaller room with music being 50% of the listening, the UFW-12 might be the choice. For a large room, primarily theater use, and needing a WAF friendly cabinet, the PB12-Plus/2 in 25 Hz tune is a great option. The point system should only be used as a guide.

4. Even though several people participated in the decision process, others will sometimes come to a different conclusion.

For example, a couple AVSers have written privately about the fact that each could buy a mint condition DD-18 for under $2500.

Considering how close the DD-18 is to the Fathom strictly in performance, AND the fact that the unit has a great built in EQ, it was a pretty easy "choice" to steer them into the Velodyne.

Great nickname "MusicFirst".
Thanks, as you can imagine, it reflects my priorities in the audio world.

Interesting you keep mentioning Hardesty and that long article he wrote in the winter, 2000 . To this day, it has remained in a stack of audio magazines on a coffee table in my 2 channel room. It's still the seminal reference article on subwoofers and his 30 pages of "Presenting The Fundamentals Parts One-Five" are required reading for anyone wanting to understand the nuances. Even though I've read it a dozen times, there's always something in there which clarifies an issue I'm mulling over.
Yeah, I feel the same way about this article, it's obvious R.H. knows his stuff when it comes to subwoofers. I look at it from time to time myself and like you usually end up picking up from it something I had not before.

There's one paragraph in his intoduction which still rings true and which makes comparisons like this one difficult. Keep in mind his frequency limits were from subs 7 years ago and wouldn't always apply today. Very true indeed, but I think that is why he created the rating system he did, to lay out for everyone, just what the strengths and weaknesses of each sub were in a very detailed manner. More info is good when it comes to investing money into this hobbie. :) Yeah, the frequency limits and SPL are much greater than they were 7 years ago in most cases.

Unfortunately to get the best of both attributes still requires a big expenditure. Lower priced subs are usually tilted one way or the other despite most manufactuers claims that their products perform well for both HT and music.Again, I couldn't agree more! :)

For those interested in this article, I still believe you can special order the WSR issue it is in directly from WSR.

1) Overall Music Reproduction
2) Overall Effects Reproduction
3) Impact
4) Tonal Defintion
5) Freedom from Overhang
6) Rhythm and Pace (ability to follow the rhythm and pace of a musical selection)
7) Midrange coloration
8) Box Integrity (freedom from audible enclosure resonance, using sine wave)
9) Distress (can the sub be easily overdriven)
10) Subjective deep bass (probably want to change to actual measured response)
11) ability to reach 105dB@35Hz (at the LP, which in R.H. case was 3 meters)
12) Ability to play at 25Hz without subsantial reduction in SPL




Good list

I would say number seven can be eliminated,as with 80hz and lower cutoff and any would be slope,you will suffer no midrange coloration.Upper bass coloration at worst.These subs should be disqualified.And stapled with the label GARBAGE.

Sound quality and built should get a solid 60-70% of the score,as without sound quality what is loudness worth...a big fat ZERO.

A subwoofer(even inexpensive) should have at least a solid,linear output down to 30hz.Else it is a bass module and subwoofers over $1000 should pass a bare minimum output barrier being set at 30Hz. 105dB measured 2m from the sub(drivers/ports),ground plane(at 30Hz).

For the very serious true audiphile subs,extension to 16Hz being a must(with true output,not just usable farts). 100dB output being a minimum at 16hz measured 1 meter from the drivers/ports.Ground plane again.

And macho subs must meet a minimum of 3 inches of linear travel ! And get a bonus of 5 points. :p

<EDIT>

...without sound quality what is loudness worth...a big fat ZERO.

<EDIT>



TheEAR, you've focused on what I believe is the most important point. What if the current line in the sand for subwoofer performance is not drawn in the right place? I do see a lot of emphasis put on maximum SPL output per driver at a given diameter. I propose that the standard be cycle-for-cycle waveform fidelity. That means correct slope, amplitude, phase, rise time and settling (not necessarily in that order!). It also means a listening space that is sufficiently damped in the low frequencies so that only the first arrival time from the subwoofer significantly contributes to bass output. Another way to achieve that is to reduce boundary reinforcement. Put your subs on bricks! By reducing room boom, I've attained remarkable improvements in definition. It should also highlight sound quality differences between subs that get drowned out otherwise. I fervently believe it would divert further sub development in a completely different direction from BIGGER-LOUDER-CHEAPER...

:)

Some items to take into consideration ...

1. Cost was not an issue nor a factor when the "number" was assigned.

2. Built in EQ was not an issue for any sub, as this can be purchased separately.

3. All subs rated 75 points and higher are recommended for both music and theater use. All these subs have some strengths and weaknesses to consider. For a smaller room with music being 50% of the listening, the UFW-12 might be the choice. For a large room, primarily theater use, and needing a WAF friendly cabinet, the PB12-Plus/2 in 25 Hz tune is a great option. The point system should only be used as a guide.

4. Even though several people participated in the decision process, others will sometimes come to a different conclusion.

For example, a couple AVSers have written privately about the fact that each could buy a mint condition DD-18 for under $2500.

Considering how close the DD-18 is to the Fathom strictly in performance, AND the fact that the unit has a great built in EQ, it was a pretty easy "choice" to steer them into the Velodyne.
so Craig, how about "size"? is that a consideration? if its not, we should have you hook up on of the "Towers" and see where it lands in the rankings! :D

so Craig, how about "size"? is that a consideration? if its not, we should have you hook up on of the "Towers" and see where it lands in the rankings! :D


So how many special request do you think it takes to break the camel's back?? :rolleyes:

So how many special request do you think it takes to break the camel's back?? :rolleyes:
craig gotta big back...dunno, but I'm trying :rolleyes:

Is going from being a Jackass to a Camel sort of like a promotion ? :D

Is going from being a Jackass to a Camel sort of like a promotion ? :D


If a Camel is a Horse designed by committee, this thread is on a similar path. :rolleyes:

sjmarcy, this is your FINAL warning.

Take a vacation from THIS thread or take a permanent vacation from AVS.
Your choice.

I will not allow you to continue de-railing this thread.

Kyser


Thanks,

http://forums.audioholics.com/forums/showthread.php?t=29188

Ddavidson

http://forums.audioholics.com/forums/showthread.php?t=29188

Ddavidson
To make it easier to read:


Why We Fired SVS as an Advertiser

--------------------------------------------------------------------------------

Several things have gone on in the past few weeks that have caused us to think about what's important to us and how we want to treat the forum community. One thing that we have realized is that at some point, when people take advantage and do not heed implied requests and basic etiquette you have to make a decision.

SVS has been an advertiser at Audioholics for some time. We like their products and continute to believe they make some of the cheapest subs out there with a good "bang for the buck" factor. Regardless of not allowing them to advertise, this has nothing to do with them as a manuafacturer.

As a company, however, their marketing methods have gotten out of control - at least on our site. If you'll notice, there is likely not a single subwoofer thread on this forum that doesn't have people talking about SVS. There is a reason for this and it has to do with the marketing methods of SVS as a company. They freely admitted to us that forum participation of their staff and SVS owners is the driving force behind their marketing strategy. This is actually kind of intelligent - until it is abused.

It is being abused on our site - to the point that we were being told that attempting to keep review threads on topic for non-SVS products was basically unacceptable behavior on our part. We were being told how to behave on our own site.

We attempted to let it go and redirect threads as needed, but a recent discussion made it clear that this was unacceptable. We STILL were going to quietly let them go on their way until a recent post appeared on our forums regurgitating the exact conversation SVS had with Gene recently.


Quote:
Originally Posted by Sjmarcy
I just joined this forum, and read a few threads. I note the declaration: "Where audio and video equipment undergoes rigorous objective and subjective tests by our staff, ensuring that marketing slogans aren't the only guidelines for your home theater choices"....yet I see the President posting encoutgement for Axiom products, a site advertiser. Hmmm. And another post where a member was called a fanboy by an Audioholic staff member on a different matter?

What's up with the difference between this sort of thing and the Forum's written mission statement?

Note the post count. This was written by someone who had a direct conversation with our contact at SVS. That pretty much did it for us.

As a result we have fired SVS as an advertiser and will enforce the following forum rules:

We will not ban SVS threads about SVS products - they make some cool subs, so people are free to talk about them as they'd like - in their own threads.
All SVS employees have been banned from the website.
We will not allow SVS posts in non-SVS review threads. I'm sorry, but it has come down to this.
Any critiques of this policy should be done via PM, not on the forums. We took a long time to come to this conclusion and we were willing to lose a lot of monthly income over this in order to make sure we don't allow our forums to become a marketing tool for a single advertiser. We are not the first (or likely last) website to enforce similar rules.
Thanks for your understanding. We hate making stuff like this public, but it seemed we were given no choice in the matter.
__________________
Clint DeBoer
Editor in Chief
Audioholics

What the hell is going on here.......

Gents ... This forum and thread are no place to post something which occured on Audioholics. Please guys, let's talk about subwoofers. :)

Gents ... This forum and thread are no place to post something which occured on Audioholics. Please guys, let's talk about subwoofers. :)
Sorry Craig.......you are right. I could not hold back.

Sorry Craig your right, but it important to see "why you where attacked here" and that with Sjmarcy repeating private stuff he is obviously in contact with SVS.

Ddavidson