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Archaea's Kansas City Blind Subwoofer Shootout 2012 - Page 15

post #421 of 735
1/23/12 at 11:21am
Quote:
Originally Posted by Archaea View Post

Oh and a second test. Our Peak SPL measurements are reading about 5-7dB lower in the back of the room where all SPL measurements were captured for the meet.

I just setup one of my dubstep songs to play through - Gold Flux Pavilion - Got 2 Know. It recorded at 113.6dB at the main listening position up front. In the back of the room, near where the control center was it measured 107.9dB.
I tested another dubstep song - Apes from Space by Aaren San, it recorded as 107.4dB from the back of the room and 114.1dB from the front.

Keep that in mind when looking at max SPLs for each sub during our blind meet. The recorded peaks are all 5-7dB lower than what the main listening position was experiencing.

Meaning that the Orbit shifter fun was all the crazier.

AND according to this chart --- we were feeling what we were supposed to with the orbit shifter in the strong mid-high 130's (if not 5-7 dB hotter in the front of the room)...

http://www.makeitlouder.com/Decibel%20Level%20Chart.txt

After standing up next to the orbit shifters my skin felt somewhat tingly, my hair felt like it was standing on end etc, every piece of my clothing was vibrating etc.

This retested info lines up with several other past measurements I've taken in months past. The HVAC support beam across the ceiling and the extra distance take it's toll on the SPL.

Great info on the measurements.

If you have any more time or itch to measure, what would be useful is to measure roughly where Husker's seat was, and then measure again at the command center where the SPL measurements were taken. His seat was reasonably close to the average, and gives a little more perspective as to what frequency ranges actually made it to the mic back there.
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post #422 of 735
1/23/12 at 3:23pm
Quote:
Originally Posted by Archaea View Post

Oh and a second test. Our Peak SPL measurements are reading about 5-7dB lower in the back of the room where all SPL measurements were captured for the meet.

I just setup one of my dubstep songs to play through - Gold Flux Pavilion - Got 2 Know. It recorded at 113.6dB at the main listening position up front. In the back of the room, near where the control center was it measured 107.9dB.
I tested another dubstep song - Apes from Space by Aaren San, it recorded as 107.4dB from the back of the room and 114.1dB from the front.

Keep that in mind when looking at max SPLs for each sub during our blind meet. The recorded peaks are all 5-7dB lower than what the main listening position was experiencing.

Meaning that the Orbit shifter fun was all the crazier.

AND according to this chart --- we were feeling what we were supposed to with the orbit shifter in the strong mid-high 130's (if not 5-7 dB hotter in the front of the room)...

http://www.makeitlouder.com/Decibel%20Level%20Chart.txt

After standing up next to the orbit shifters my skin felt somewhat tingly, my hair felt like it was standing on end etc, every piece of my clothing was vibrating etc.

This retested info lines up with several other past measurements I've taken in months past. The HVAC support beam across the ceiling and the extra distance take it's toll on the SPL.

I mentioned this before, but the readings that you recorded on Ominimic regarding SPL levels are likely inflated. You mentioned that you only observed and recorded the 'Peak' value on Omnimic. If I understand this correctly, this value is not same value you would observe on an SPL meter. To compare it to an SPL meter, you should use the 'Max' value. That mirrors what a typical SPL meter measures. The 'Peak' value is just the highest point of the waveform, as there is no time component to it. The 'Max' is measured in RMS.

I did a quick google and found this for a better explanation: http://www.noisemeters.com/help/faq/min-max-peak.asp

In my tests, the omnimic recorded a Peak value that was typically 8-10db higher than the 'Max' value. Assuming yours measures roughly the same, you could extrapolate your measurements by that much to get the 'Max' values. So for the orbital shifter, it was probably more like mid to high 120s instead of 130s. All the other subs (generally speaking) are also around 8-10db less to get the 'SPL' meter value.
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post #423 of 735
1/23/12 at 4:28pm
Thread Starter 
Quote:
Originally Posted by dominguez1 View Post

I mentioned this before, but the readings that you recorded on Ominimic regarding SPL levels are likely inflated. You mentioned that you only observed and recorded the 'Peak' value on Omnimic. If I understand this correctly, this value is not same value you would observe on an SPL meter. To compare it to an SPL meter, you should use the 'Max' value. That mirrors what a typical SPL meter measures. The 'Peak' value is just the highest point of the waveform, as there is no time component to it. The 'Max' is measured in RMS.

I did a quick google and found this for a better explanation: http://www.noisemeters.com/help/faq/min-max-peak.asp

In my tests, the omnimic recorded a Peak value that was typically 8-10db higher than the 'Max' value. Assuming yours measures roughly the same, you could extrapolate your measurements by that much to get the 'Max' values. So for the orbital shifter, it was probably more like mid to high 120s instead of 130s. All the other subs (generally speaking) are also around 8-10db less to get the 'SPL' meter value.

from your article link -

"The [peak] is used for occupational noise measurement where loud bangs are present."

Isn't that sort of representative of what we were auditioning?

From that article - if I understand correctly the max value would represent the 'repeating' max spls levels in the source material... whereas the peak would represent the highest spl levels measured even if for the briefest of moments in a dynamic swing (explosion ect). I can play back a couple songs or media pieces and see how much difference there is between max and peak in normal material. You are correct the max numbers were lower than the peak numbers, but I didn't pay close enough attention to know how much they varied in my room.

From the screenprint of the orbit shifters we hit 134dB peak and 124dB max (in the back of the room). I can tell you I've had a Radio Shack SPL meter hit 125 repeating in my room on dubstep while tapping the clip lights from the main listening position(front of the room), c weighted and slow measurement selected on RS meter. This was done while playing with my Cap Pros on my EP4000 amp. I can absolutely guarantee the Orbit shifters were a lot louder than the 125dB measurement gathered off the Radio Shack SPL meter in my room!!!! So unless the rat shack meter is measuring peaks (and it might be???!!) then we were hitting a lot louder than low 120 dBs with the orbit shifters. My kitchen tile grout will tell you this same tale.

Is peak reading then considered worthless?
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post #424 of 735
1/23/12 at 4:52pm
Quote:
Originally Posted by Archaea View Post

from your article link -

"The [peak] is used for occupational noise measurement where loud bangs are present."

Isn't that sort of representative of what we were auditioning?

From that article - if I understand correctly the max value would represent the 'repeating' max spls levels in the source material... whereas the peak would represent the highest spl levels measured even if for the briefest of moments in a dynamic swing (explosion ect). I can play back a couple songs or media pieces and see how much difference there is between max and peak in normal material. You are correct the max numbers were lower than the peak numbers, but I didn't pay close enough attention to know how much they varied in my room.

From the screenprint of the orbit shifters we hit 134dB peak and 124dB max (in the back of the room). I can tell you I've had a Radio Shack SPL meter hit 125 repeating in my room on dubstep while tapping the clip lights from the main listening position(front of the room), c weighted and slow measurement selected on RS meter. This was done while playing with my Cap Pros on my EP4000 amp. I can absolutely guarantee the Orbit shifters were a lot louder than the 125dB measurement gathered off the Radio Shack SPL meter in my room!!!! So unless the rat shack meter is measuring peaks (and it might be???!!) then we were hitting a lot louder than low 120 dBs with the orbit shifters. My kitchen tile grout will tell you this same tale.

Is peak reading then considered worthless?

For SPL measurements that we hear, I believe so. I'm no expert on the subject, so someone feel free to chime in. This is how it was explained to me by another forum member, who had spoken directly with Bill (Omnimic).

Regarding the Shifters and Caps, don't know. I would guess it depends what frequency hit that max. If it were a higher freq than the caps, that may explain the shifters more tactile perception of being louder...as well as explain your grout.
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post #425 of 735
1/24/12 at 8:41am
Desertdome came over and we measured the Seaton/MCCA Modified Dayton SA-1000 that Kevin (Sandbagger) sent for the Omaha GTG in October. We never got to test that amp with the dual opposed since we ran out of time.
We also ran the numbers on the Dayton SA-1000 that is unmodded and compared the two.

Equipment used was the same as from the Omaha GTG. The Steinberg and ECM8000 calibrated by CSL to 5hz. J River Media Center was used for applying the REW filters and L/T, etc. We placed the ECM8000 in the same position as the October GTG, so if you want to go back and look at how the room looks from that mic standpoint, you can.

Link to description of EQ from Omaha GTG. SubFest 2011 EQ Methods

I think I'm eventually going to get rid of my Onkyo and use one of Desertdome's Steinbergs and J River. J River is a powerful tool, and the more I see its uses I don't think anything is as easy or seamless to use and apply filters. That and REW are quite the match.

It just doesn't run Height channels. Boo.


It is pretty cool what you can do if you are into EQ and can use REW and J River and apply filters and tweak. In 30 minutes you can copy the hours of work I'm sure it took Mark or Kevin to modify the SA1000.

BUT, say you don't have that capability or feel like doing that.

The modded SA1000 is a nice option for those DIYs that have all of those MFW-15 drivers in boxes. For a bit of an upcharge you can buy a modded amp like this.

This might be an option for CHT owners of the 18.1/18.2. I wonder with their experience with the SA-1000 if they could mod the amp to help owners out there for an even better response---or any other amps in general?

Could be a cool service.

The graphs are pretty self-explanatory, Seaton and Dayton close mics taken from the same dual opposed, 1 inch from dustcap. Room is with the mic in the position from the Omaha GTG, LT as applied by J River (adjusted using RTA), and EQ utilizing filters as suggested by REW.

Desertdome please add things I screwed up.

If anyone wants different overlays let me know.
LL
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post #426 of 735
1/24/12 at 8:52am
Speaking of the MFW-15 drivers, some folks are still waiting for Mark or Kevin to update their webpage with the cost of the cabinets, etc.

James
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post #427 of 735
1/24/12 at 8:56am
Quote:
Originally Posted by exojam View Post

Speaking of the MFW-15 drivers, some folks are still waiting for Mark or Kevin to update their webpage with the cost of the cabinets, etc.

James

Are they aware of any interest?
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post #428 of 735
1/24/12 at 9:01am
They do have a thread over on the MCCA section of Marks site where they had put together a cabinet for 2 drivers but nothing has been updated since November. There had been a few folks inquiring about it but it does not appear to be moving anywhere (I had not registered there but I do keep an eye on it). It could be a lower priority for both of the guys though.

James
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post #429 of 735
1/24/12 at 9:37am
Quote:
Originally Posted by exojam View Post

They do have a thread over on the MCCA section of Marks site where they had put together a cabinet for 2 drivers but nothing has been updated since November. There had been a few folks inquiring about it but it does not appear to be moving anywhere (I had not registered there but I do keep an eye on it). It could be a lower priority for both of the guys though.

James

It's been buried a little under many other things going on. I need to re-quote it and offer those. I'm planning to probably move that to WW Speakercabinets to sell directly once we get that set up. There should be some movement on that in February.
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post #430 of 735
1/24/12 at 9:55am
Quote:
Originally Posted by HuskerOmaha View Post

Desertdome came over and we measured the Seaton/MCCA Modified Dayton SA-1000 that Kevin (Sandbagger) sent for the Omaha GTG in October. We never got to test that amp with the dual opposed since we ran out of time.
We also ran the numbers on the Dayton SA-1000 that is unmodded and compared the two.

Equipment used was the same as from the Omaha GTG. The Steinberg and ECM8000 calibrated by CSL to 5hz. J River Media Center was used for applying the REW filters and L/T, etc. We placed the ECM8000 in the same position as the October GTG, so if you want to go back and look at how the room looks from that mic standpoint, you can.

Link to description of EQ from Omaha GTG. SubFest 2011 EQ Methods

I think I'm eventually going to get rid of my Onkyo and use one of Desertdome's Steinbergs and J River. J River is a powerful tool, and the more I see its uses I don't think anything is as easy or seamless to use and apply filters. That and REW are quite the match.

It just doesn't run Height channels. Boo.


It is pretty cool what you can do if you are into EQ and can use REW and J River and apply filters and tweak. In 30 minutes you can copy the hours of work I'm sure it took Mark or Kevin to modify the SA1000.

BUT, say you don't have that capability or feel like doing that.

The modded SA1000 is a nice option for those DIYs that have all of those MFW-15 drivers in boxes. For a bit of an upcharge you can buy a modded amp like this.

This might be an option for CHT owners of the 18.1/18.2. I wonder with their experience with the SA-1000 if they could mod the amp to help owners out there for an even better response---or any other amps in general?

Could be a cool service.

The graphs are pretty self-explanatory, Seaton and Dayton close mics taken from the same dual opposed, 1 inch from dustcap. Room is with the mic in the position from the Omaha GTG, LT as applied by J River (adjusted using RTA), and EQ utilizing filters as suggested by REW.

Desertdome please add things I screwed up.

If anyone wants different overlays let me know.


Are those high passed at like 15? Looks like it with the preceding hump before 15 and then drops like a rock.....
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post #431 of 735
1/24/12 at 10:02am
Quote:
Originally Posted by NicksHitachi View Post


Are those high passed at like 15? Looks like it with the preceding hump before 15 and then drops like a rock.....

On the stock Dayton we put a hpf at 14 I believe.
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post #432 of 735
1/24/12 at 10:48am
Quote:
Originally Posted by Mark Seaton View Post

It's been buried a little under many other things going on. I need to re-quote it and offer those. I'm planning to probably move that to WW Speakercabinets to sell directly once we get that set up. There should be some movement on that in February.

Mark,

Thanks for the information. I figured it was probably just down the ladder of things to get moving.

James
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post #433 of 735
1/24/12 at 11:03am
Quote:
Originally Posted by HuskerOmaha View Post


On the stock Dayton we put a hpf at 14 I believe.

Why?
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post #434 of 735
1/24/12 at 12:12pm
Quote:
Originally Posted by NicksHitachi View Post

Why?

Actually there wasn't a high pass for these measurements. If you look at the Subfest 2011 GTG (link in HuskerOmaha's sig) you will see that all the sealed subs dropped off in his room at that same frequency. The only sub that had the output come back up at about 10 Hz was the Submersive. The rolloff at the GTG of the CHT 18.2 (also using the Dayton amp) is identical.

We are going to take a few measurements this evening and maybe we can check with a different amp besides the Dayton.
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post #435 of 735
1/24/12 at 12:54pm
Quote:
Originally Posted by desertdome View Post

Actually there wasn't a high pass for these measurements. If you look at the Subfest 2011 GTG (link in HuskerOmaha's sig) you will see that all the sealed subs dropped off in his room at that same frequency. The only sub that had the output come back up at about 10 Hz was the Submersive. The rolloff at the GTG of the CHT 18.2 (also using the Dayton amp) is identical.

We are going to take a few measurements this evening and maybe we can check with a different amp besides the Dayton.

I'd be suspicious of the Dayton as well. Most folks running bunches of sealed MFWs on pro power are not seeing that kinda drop off. Could be the room I guess, big room? No gain?

I have also read that the Dayton has issues on the really low stuff.

Just looks like a lot was left on the table so to speak...... A big hole 10-15Hz is a pretty big issue, and a sealed multiple setup that rolls at 15 deserves some investigation.

I'm interested in what you'll find.
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post #436 of 735
1/24/12 at 12:57pm
Quote:
Originally Posted by NicksHitachi View Post


I'd be suspicious of the Dayton as well. Most folks running bunches of sealed MFWs on pro power are not seeing that kinda drop off. Could be the room I guess but I've never seen a room suckout that broad and intense that low.....

I have also read that the Dayton has issues on the really low stuff.

Just looks like a lot was left on the table so to speak...... A big hole 10-15Hz is a pretty big issue, and a sealed multiple setup that rolls at 15 deserves some investigation.

I'm interested in what you'll find.

I'd hook my LG clone amp up and see what we get but oh wait it is dead.

Maybe Desertdome can bring his Face amps over or Cherry amps and we can try those.
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post #437 of 735
1/24/12 at 1:28pm
Quote:
Originally Posted by HuskerOmaha View Post

Maybe Desertdome can bring his Face amps over or Cherry amps and we can try those.

One of my Face F1200TS amps is in the car and ready to bring over.
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post #438 of 735
1/24/12 at 1:38pm
Quote:
Originally Posted by desertdome View Post

One of my Face F1200TS amps is in the car and ready to bring over.

Im staring at the dsp settings and the 14 hz hpf is still on in JRiver.

I'd run the stuff again and post without it but everything is falling below 50 hz and lower with the pink noise through RTA. I forgot how to fix that.

The Seaton curve is of course without eq.
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post #439 of 735
1/24/12 at 1:55pm
Quote:
Originally Posted by HuskerOmaha View Post

This might be an option for CHT owners of the 18.1/18.2. I wonder with their experience with the SA-1000 if they could mod the amp to help owners out there for an even better response---or any other amps in general?

I'd like to try this, if you have the time.
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post #440 of 735
1/24/12 at 1:59pm
Quote:
Originally Posted by tesseract67 View Post

I'd like to try this, if you have the time.

REW and JRiver, EQ? I wouldn't have the slightest on how to actually mod the amp like MCCA/Seaton. Wouldn't want to try either.
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post #441 of 735
1/24/12 at 2:09pm
No, I'd like to try the Seaton/MCCA Modified Dayton SA-1000 with the 18.Ts.

Although I am gearing up for REW. JRiver would be a nice addition.
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post #442 of 735
1/24/12 at 2:15pm
Quote:
Originally Posted by tesseract67 View Post

No, I'd like to try the Seaton/MCCA Modified Dayton SA-1000 with the 18.Ts.

Although I am gearing up for REW. JRiver would be a nice addition.

They EQd the amp specifically for the mfw15 I think. Mark can chime in, I'm not sure what we would see.... graph wise.
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post #443 of 735
1/24/12 at 2:22pm
Is it EQ'ed for the MFW-15 Turbo, or the dual opposed?
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post #444 of 735
1/24/12 at 2:24pm
Yes the amp is specifically EQd and limited for the MFW-15 in the 2.5-3.0ft box.

I am guessing its going to be an ugly looking curve??

also I would use a lot closer distance than 1" as your seeing a lot of room interactions going on still. If you go and look at the graph I have posted of the response you will see it



Quote:
Originally Posted by HuskerOmaha View Post

They EQd the amp specifically for the mfw15 I think. Mark can chime in, I'm not sure what we would see.... graph wise.
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post #445 of 735
1/24/12 at 2:24pm
Quote:
Originally Posted by tesseract67 View Post

No, I'd like to try the Seaton/MCCA Modified Dayton SA-1000 with the 18.Ts.

Although I am gearing up for REW. JRiver would be a nice addition.

Remember that Husker & Desertdome had an easy target to match. Pulling the sub in the middle of the room and measuring at ~3/8" from the cone would give a nicer looking curve to work from, as their NF measurement still contains a lot of room in it. While they are likely related, the curve for the MFW drivers will be different than Kevin & I would dial in for the 18.T/18.2, as the goal is to match and smooth the outdoor response to a target, while also adjusting to keep the sub from overloading. An appropriately matching mod can be derived if Kevin or I took the measurements we need on the intended sub.

Husker/Desertdome, please run Open Range, Iron Man-Jericho, or the KFP skadoosh scene with both of those amps powering all 4 MFW-15 drivers and keep turning the level up. The stock amp would have been very obvious if used at the GTG.
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post #446 of 735
1/24/12 at 2:25pm
The amp they have is specifically for a dual or quad of MFW-15 drivers in a 2.5-3.0ft^3 box. It is very very different to that of a turbo upgrade kit.

Quote:
Originally Posted by tesseract67 View Post

Is it EQ'ed for the MFW-15 Turbo, or the dual opposed?
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post #447 of 735
1/24/12 at 2:38pm
If not tonight, maybe thursday. We will rerun in center of room....and do the demo tracks...
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post #448 of 735
1/24/12 at 2:43pm
Quote:
Originally Posted by Mark Seaton View Post

Remember that Husker & Desertdome had an easy target to match. Pulling the sub in the middle of the room and measuring at ~3/8" from the cone would give a nicer looking curve to work from, as their NF measurement still contains a lot of room in it. While they are likely related, the curve for the MFW drivers will be different than Kevin & I would dial in for the 18.T/18.2, as the goal is to match and smooth the outdoor response to a target, while also adjusting to keep the sub from overloading. An appropriately matching mod can be derived if Kevin or I took the measurements we need on the intended sub.

Things that make you go... hmmm.

This is something for me to consider. Most people are good with Audyssey doing the Eq'ing, but I am two channel minimalist and depend upon an amp filter or something new, like JRivers.

I am considering adding another 18.T Duo, which will need some EQ, or just going the easy route of dual vented VS-18.1s and stock Dayton.
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post #449 of 735
1/25/12 at 9:24am
HuskerOmaha and I measured the stock Dayton SA1000 amp vs a Face F1200TS amp using a close mic on the dual opposed MFW-15 drivers. The Dayton amp had the bass boost on and subsonic filter off. There was no high pass filter in place for either amp. We also measured the Dayton amp with the bass boost off, but inadvertently deleted the measurement later on.

You can see that on the Dayton the bass boost is giving about a 3 dB boost at 25. According the the manual, the boost is a PEQ with a 3 dB gain and 1.4 Q at 25 hz. Below 16 Hz, the Dayton amp is dropping lower than the Face amp and is down 4 dB at 10 Hz. With a 1.4 Q/25 Hz PEQ, the Dayton should start boosting at 60 Hz and finish the boost at 10 Hz.

The blue line is the Dayton and green is the Face.
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post #450 of 735
1/25/12 at 10:03am
Thread Starter 
Desertdome - interesting. I wonder why the difference? We saw the Dayton 25hz bass boost do a more uniform bump across the whole frequency range at my place when we tested it on Sunday after the blind meet with the CHT subs. Full info in post #360 of this thread.

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