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-   -   Official Rythmik Audio Subwoofer thread (https://www.avsforum.com/forum/113-subwoofers-bass-transducers/1214550-official-rythmik-audio-subwoofer-thread.html)

jpmst3 01-28-2010 09:03 PM

Quote:
Originally Posted by FlavioSupra View Post


How much output will I lose at the bottom end?
My room is appr. 8000 cu.ft.
My main speakers are Def Tech Mythos ST playing as full range speakers.
For movies I always listen at reference level and when I listen to music I also like to play it loud.

You will lose some significant output down low. Above 30Hz it should be close, but you can't compete against larger ported boxes with small sealed.

panzer 01-29-2010 07:33 AM

I have a question on the d15se, looking at the back on the websight, I don't see a life input, I will be using my receiver sub out, wich input on the sub would I use, and what would be the settings on the back of sub, thanks

rick240 01-29-2010 07:38 AM

Quote:
Originally Posted by panzer View Post

I have a question on the d15se, looking at the back on the websight, I don't see a life input, I will be using my receiver sub out, wich input on the sub would I use, and what would be the settings on the back of sub, thanks

Either L or R line level input.

polarbare 02-02-2010 12:26 AM

Quick question - been reading around for a bit, and I can't seem to find a definite answer, is there any reason to go with the F12SE vs the F15SE (or vice versa)? Is the F12 any "faster" and better for music (as opposed to home theater) and the F15 just able to reach lower? Or is it merely a size constraint/room compatibility/cost issue?

One other thing - the F15SE is only available through the Rythmic website, whereas the F12SE is only available through the Ascend website. Just an indication of supply at each location?

Last edit I presume the F12SE's on the Ascend website have the A370PEQ amplifier.

cschang 02-02-2010 01:58 AM

1 Attachment(s)
Quote:
Originally Posted by polarbare View Post

Quick question - been reading around for a bit, and I can't seem to find a definite answer, is there any reason to go with the F12SE vs the F15SE (or vice versa)? Is the F12 any "faster" and better for music (as opposed to home theater) and the F15 just able to reach lower? Or is it merely a size constraint/room compatibility/cost issue?

One other thing - the F15SE is only available through the Rythmic website, whereas the F12SE is only available through the Ascend website. Just an indication of supply at each location?

Last edit I presume the F12SE's on the Ascend website have the A370PEQ amplifier.

The difference between the two is essentially just their output capabilities. Some have said that the F12 has a bit better sound quality.

The Ascend site needs to be updated. Any Rythmik sub is available via Ascend and vice versa.

Upgrader 02-02-2010 09:12 PM

At http://www.rythmikaudio.com/F12.html it says that all products are on back-order. The post on this thread by Rythmik says they will have stock in 6 weeks. Does that mean to check back around mid-March?

powbob01 02-03-2010 01:51 PM

Everything looks to be in stock now.

rick240 02-03-2010 02:07 PM

Quote:
Originally Posted by powbob01 View Post

Everything looks to be in stock now.

From the Rythmik site on the F12 page

Quote:


We are currently out of these subwoofers. The new ones will be available in early March.


stevec325 02-03-2010 03:22 PM

Looking at the freq response chart for the F12 signature, it looks like it really drops off above 80Hz. And, it's way down at/above 100Hz. Any thoughts as to how that will integrate with mains crossed at 80Hz? I was under the impression that you needed "usable" output up to around 140-160Hz, even crossing at 80Hz to overlap a full octave.

Thoughts? Comments?

rick240 02-03-2010 04:20 PM

Quote:
Originally Posted by stevec325 View Post

Looking at the freq response chart for the F12 signature, it looks like it really drops off above 80Hz. And, it's way down at/above 100Hz. Any thoughts as to how that will integrate with mains crossed at 80Hz? I was under the impression that you needed "usable" output up to around 140-160Hz, even crossing at 80Hz to overlap a full octave.

Thoughts? Comments?

My reading of that chart says that it is down 3-4 db at 100Hz and down about 10db at 160 Hz.

tegage 02-03-2010 04:29 PM

Quote:
Originally Posted by monomer View Post

I suggest in addition to single freq tones you also try an actual sweep so you get an idea of the broadness (or narrow) of the nulls you are hearing. You can go here and download an MP3 file of a slow 10-200Hz sweep from Bass Mekanik for $.89 (its #109 on my screen listing)... or you go here and install SigJenny (a freeware signal generator) and play and create your sweep wav files. Was that 50Hz drop interaction between your mains and the sub or just your mains (between each other)? Try only the mains by themselves to determine if it is due to placement of the mains. Also was this 50Hz drop after you ran Audyssey (proper phasing between sub and mains were set)? Its important to remember that a cross-over is not a "brick-wall" but only identifies the mid (50/50) cross-over point. Your mains will still have a significant effect (albeit decreasing) down to an octave below the cross-over, just as the sub will have an effect (also decreasing in significance) to around an octave above the cross-over. If you set you crossover to 80Hz then the region of cross-over is ~40-160Hz. Have you tried the sub in another location yet?

OK, I moved the mains a bit (not much), turned off the PEQ and set the bass extension at 14/high and then I re-ran Audessey.

The results seem much better - in fact I'm wondering if during my initial setup I got something out of order. Anyway - with the sub and mains, it looks like this:

20Hz, 0
25Hz, +1
31.5Hz, +2
40Hz,+7
50Hz, +4
63Hz, +9
80Hz, +8
100Hz,+15
125Hz, -3

With only the sub, it looks like this:
20Hz, -1
25Hz, 0
31.5Hz, 0
40Hz, 0
50Hz, -4
63Hz, -15
80Hz, -9
100Hz,-20
125Hz, -25

So, this time around things are reasonably flat except at 100, which is solely due to the Lsi15s (Mains).

The whole system is sounding very good to me. I've been listening to a lot of music, and the sound is incredible. To be fair, I added the Lsi15s at the same time and I think they are incredible, but prior to this change, I never used my old Velodyne for music - it sounded too mushy - the Rythmik sounds good.

I watched Taken the other night and was pleased with what I could "feel" during a couple of the action scenes. I will report more back as I watch more movies.

powbob01 02-03-2010 05:38 PM

Quote:
Originally Posted by rick240 View Post

From the Rythmik site on the F12 page

When I looked before instead of the order now button there was an out of stock quote. I guess that changed.

mookie b 02-03-2010 06:54 PM

Did anyone here compare the F12 with the SVS SB12?

stevec325 02-03-2010 08:10 PM

Quote:
Originally Posted by rick240 View Post

My reading of that chart says that it is down 3-4 db at 100Hz and down about 10db at 160 Hz.

Does that seem OK for drop off at the upper end?

Iain- 02-04-2010 08:56 AM

I'm keen to see how the new 370PEQ amplifiers, supposedly with extended frequency range to 180 HZ, will integrate with GR Research 12" driver (F12G).

monomer 02-04-2010 09:56 AM

Quote:
Originally Posted by tegage View Post

OK, I moved the mains a bit (not much), turned off the PEQ and set the bass extension at 14/high and then I re-ran Audessey.

The results seem much better - in fact I'm wondering if during my initial setup I got something out of order. Anyway - with the sub and mains, it looks like this:

20Hz, 0
25Hz, +1
31.5Hz, +2
40Hz,+7
50Hz, +4
63Hz, +9
80Hz, +8
100Hz,+15
125Hz, -3

With only the sub, it looks like this:
20Hz, -1
25Hz, 0
31.5Hz, 0
40Hz, 0
50Hz, -4
63Hz, -15
80Hz, -9
100Hz,-20
125Hz, -25

So, this time around things are reasonably flat except at 100, which is solely due to the Lsi15s (Mains).

The whole system is sounding very good to me. I've been listening to a lot of music, and the sound is incredible. To be fair, I added the Lsi15s at the same time and I think they are incredible, but prior to this change, I never used my old Velodyne for music - it sounded too mushy - the Rythmik sounds good.

I watched Taken the other night and was pleased with what I could "feel" during a couple of the action scenes. I will report more back as I watch more movies.

Did you remember to apply the correction factors to your SPL readings above?... if not and its a RS meter, then your response is even flatter than you think. There's a chance that 100Hz peak can be attenuated by further 'tweaking' of the speaker positions (meaning the mains only) if they are interacting with each other (due to distance both between them and to you) and if not then it must be cause by a room reflection or a mode and some room acoustical treatments might then be in order. Looks like you've got a good starting point and are now beginning to hear what the 'real' Rythmik sounds like.

tegage 02-04-2010 11:12 AM

Quote:
Originally Posted by monomer View Post

Did you remember to apply the correction factors to your SPL readings above?...

It is a RS meter, but I wasn't aware that there are correction values.

A quick google uncovered them, the with the corrections, I have:

20Hz, +7.5
25Hz, +6
31.5Hz, +5
40Hz,+9.5
50Hz, +6.5
63Hz, +10.5
80Hz, +9.5
100Hz,+17
125Hz, -2.5

Other than the spike at 100 and drop at 125, am I correct that in typical home setup, what I have up to 100 Hz is pretty good/normal?

monomer 02-04-2010 11:59 AM

Quote:
Originally Posted by tegage View Post

It is a RS meter, but I wasn't aware that there are correction values.

A quick google uncovered them, the with the corrections, I have:

20Hz, +7.5
25Hz, +6
31.5Hz, +5
40Hz,+9.5
50Hz, +6.5
63Hz, +10.5
80Hz, +9.5
100Hz,+17
125Hz, -2.5

Other than the spike at 100 and drop at 125, am I correct that in typical home setup, what I have up to 100 Hz is pretty good/normal?

Though you can use EQing to flatten it even more those types of EQs work on one "sweet spot" only, which is great if you listen solo from the same position only because you can dial it in just for that one location without caring about what the effect is upon any other listening position in the room... HOWEVER, if you listen to music together with others or watch movies with friends and family or like to change positions when listening music or watching movies then EQing for a single "sweet spot" just doesn't get it. I like Audyssey because it tries to find the best compromise across all listening positions (considers the effect on a larger listening area)... creating sort of a "sweet area" so to speak. Under those conditions, YES! your results are quite good as your ears have already verified and you should be proud. However, this IS 'the hobby of audio'... so the nitpicking is never done... all we ever succeed at doing is raising our standards to the next level. Once your pocketbook has recovered sufficiently, it will be time to visit forums on acoustical room treatments...

mattldm 02-08-2010 07:51 PM

Quote:
Originally Posted by rick240 View Post

Hey Brian,

I've been really enjoying my F12.

Have you ever thought of going the other size direction and building a F10 for those with sub size constraints?

I agree! I would be interested in a smaller version, maybe a 10"

In fact right now im thinking of DIY'ing a 10-12" sub with the A370PEQ amp just to have a smaller sub to fit where I want it to go!

porksoda 02-25-2010 02:14 PM

Quote:
Originally Posted by mookie b View Post

Did anyone here compare the F12 with the SVS SB12?

I would be interested in comments to this as well... and throw in paradigm sub 12 / 15

stevec325 02-25-2010 02:19 PM

Brian, when are the new F12-SE's going to release?

It's been very quiet.

Rythmik 02-27-2010 07:02 AM

I have F12 black oak and F12SE arrived yesterday. They will begin shipping on Monday and so does the DS1200 kit. This shipment is mainly with black cone DS1200. I do have a few silver drivers. But when possible, please stay with black cone drivers. If you must have silver cone, don't be disappointed as I do have a few silver cone DS1200 available.

Arrived with the above is the new 15" driver -- model number DS1510. It has a 3" voice coil and can be driven by H600PEQ servo amp. The cone style is 1 piece aluminum dish cone, similar to our F12/F12SE drivers (in comparison DS1501 is two piece silver aluminum cone construction with dust cover). The only cone color available is black anodized. Since in the past I have two customers returning subs simply because the spouse were shocked or spooked by the size of F15, I have a new enclosure for these DS1510/H600 combination. Its model number is E15. I will fill in the size later. But basically DS1510/H600 can be installed either in E15 enclosure or F15 enclosure. One thing to note is the basket sizes of DS1500 and DS1510 are different by 1.5mm in diameter, they are not directly swappable in the most strict sense. For us, F15 used for DS1510 has a smaller recess diameter.

I would also like to get your feedback about the new features on PEQ2 amp. From now on, all finished subwoofers using 370WRMS amp will ship with A370PEQ2 amps (whereas H500PEQ and H600PEQ will still have original A370PEQ's control features). The new PEQ2 has two newly added functions: 1) defeatable limiter and 2) LFE low pass filter setting that extends the upper subwoofer frequency response to 180hz. I would like to hear feedback about: 1) If you can hear the coloration introduced by limiter by comparing the sound with limiter on and off using the music you are most familiar, and 2) If AVR/12 setting and LFE has made an audible difference and which of these two settings you like best?

Also important is the kits will continue to ship with A370PEQ amps. Therefore we will create two completely different lines of amplifiers moving forward, one for kit and one for completed subwoofers so the customers of the latter don't feel the value of their subwoofers is diluted by kits.

Lastly, several customers ask about the availability of DS1500 drivers and hence all F15 and D15SE silver cone subwoofers. They will arrive by end of March.

The size of E15 enclosure is 17" wide, 19" tall. 18" deep without grille and back control depth. Grille adds 1" and back control knobs add 1". In comparison, the F15 is 2" wider and 1" deeper. The narrower and taller baffle size makes it looked smaller. BTW, F15 is not really too big for my taste :-)

Here is the introductory pricing:
E15 black oak finish with DS1510 black cone and 600WRMS servo amp: $1099.
E15 piano black finish with DS1510 black cone and 600WRMS servo amp: $1249.

The same pricing for F15 enclosures with the above driver/amplifier combination.

xcjago 02-27-2010 09:09 AM

Any status on the F12 in satin black?

Rythmik 02-27-2010 03:43 PM

Quote:
Originally Posted by xcjago View Post

Any status on the F12 in satin black?

It will be in the next batch, which is estimated to be 2-3 months.

Rythmik 02-27-2010 03:54 PM

There have been questions about the difference in extension among our various sealed subwoofers. The short answer is they all have the same extension. The only difference is the maximum output capability. This is a design feature. The reason for that is very simple. We have a extension filter setting to let customer select the extension suitable for their based on their habits. If one wants to play loud, then one can use 28hz low damping setting, instead of 14hz, high damping setting. It is also a future-thinking feature. If we had made the F12 lesser extension than F15, that would limit the upgrade path from F12 to go with bigger subwoofer, instead of just add another F12 subwoofer.

In addition, the decision between 12" sub and 15" subs should also depend on the woofer size in the front speakers. If the front speakers also have 6-1/2" woofer or bigger, there is no point of using 12" subs.

atroder 02-27-2010 04:34 PM

Brian, I don't seem to be getting thru via email, so am posting here. I'm interested in the F12 honey oak, A370PEQ2. Are they available? - thanks

lewdogg 02-27-2010 04:51 PM

Quote:
Originally Posted by Rythmik View Post

I have F12 black oak and F12SE arrived yesterday. They will begin shipping on Monday and so does the DS1200 kit. This shipment is mainly with black cone DS1200. I do have a few silver drivers. But when possible, please stay with black cone drivers. If you must have silver cone, don't be disappointed as I do have a few silver cone DS1200 available.

Arrived with the above is the new 15" driver -- model number DS1510. It has a 3" voice coil and can be driven by H600PEQ servo amp. Since in the past I have two customers returning subs simply because the spouse were shocked by the size of F15, I have a new enclosure for these DS1510/H600 combination. Its model number is E15. I will fill in the size later. But basically DS1510/H600 can be installed either in E15 enclosure or F15 enclosure. One thing to note is the basket sizes of DS1500 and DS1510 are different by 1.5mm in diameter, they are not directly swappable in the most strict sense. For us, F15 used for DS1510 has a smaller recess diameter.

I would also like to get your feedback about the new features on PEQ2 amp. From now on, all finished subwoofers using 370WRMS amp will ship with A370PEQ2 amps (whereas H500PEQ and H600PEQ will still have original A370PEQ's control features). The new PEQ2 has two newly added functions: 1) defeatable limiter and 2) LFE low pass filter setting that extends the upper subwoofer frequency response to 180hz. I would like to hear feedback about: 1) If you can hear the coloration introduced by limiter by comparing the sound with limiter on and off using the music you are most familiar, and 2) If AVR/12 setting and LFE has made an audible difference and which of these two settings you like best?

Also important is the kits will continue to ship with A370PEQ amps. Therefore we will create two completely different lines of amplifiers moving forward, one for kit and one for completed subwoofers so the customers of the latter don't feel the value of their subwoofers is diluted by kits.

Lastly, several customers ask about the availability of DS1500 drivers and hence all F15 and D15SE silver cone subwoofers. They will arrive by end of March.

Any sneak peeks of the E15?

DJLEC 02-28-2010 10:19 AM

Need some help in deciding what sub to order.

I am 100% HT and presently using two REL Storm III subs. They have a 10" Driver with a 150 W to 300W peak amp. As you can see in the attached pictures I am using one REL on either side of the room behind the couch (TV at the other end on the short wall).

Not getting the slam from the REL's that I desire so I have the opinion of getting one sub. I am very limited where to put the sub and what you see in the pictures is the best I can do. Room is extensively trapped with ASC Tube Traps.

Room is 22' L x 13' W x 10' H (Average since it is peaked) which equals 2,860 cubic feet.

Would prefer not to get crazy here so F12 would be the range I am looking for in price and size.

Any thoughts would be appreciated and it is likely I will call Rythmic tomorrow.

Thanks in advance,


David
LL
LL
LL

Rythmik 02-28-2010 10:29 AM

Quote:
Originally Posted by atroder View Post

Brian, I don't seem to be getting thru via email, so am posting here. I'm interested in the F12 honey oak, A370PEQ2. Are they available? - thanks

Yes. They are available.

stevec325 02-28-2010 11:38 AM

Quote:
Originally Posted by Rythmik View Post


I would also like to get your feedback about the new features on PEQ2 amp. From now on, all finished subwoofers using 370WRMS amp will ship with A370PEQ2 amps (whereas H500PEQ and H600PEQ will still have original A370PEQ's control features). The new PEQ2 has two newly added functions: 1) defeatable limiter and 2) LFE low pass filter setting that extends the upper subwoofer frequency response to 180hz. I would like to hear feedback about: 1) If you can hear the coloration introduced by limiter by comparing the sound with limiter on and off using the music you are most familiar, and 2) If AVR/12 setting and LFE has made an audible difference and which of these two settings you like best?

Brian,

The new graphs on the website reflect these new PEQ's - right?

The upper extension is just what I was looking for to bring the -3dB point well above 100Hz.

Thanks!!!

David Rad 03-01-2010 10:56 AM

Hi Brian,

Can you tell us how much energy the F12 with the new amplifier consumes in standby mode? Also, when in standby mode, how long does it take for subwoofer to kick in after receiving a signal, and after what time does it go off?

Rythmik 03-01-2010 10:07 PM

Quote:
Originally Posted by David Rad View Post

Hi Brian,

Can you tell us how much energy the F12 with the new amplifier consumes in standby mode? Also, when in standby mode, how long does it take for subwoofer to kick in after receiving a signal, and after what time does it go off?

For PEQ2 amps, I take out the auto-on function. So there is no more auto-on switch. I used that switch to implement the limiter on/off function. The reason is simple. The power saving with an auto-on on these class A/B amps is only 2W. When the power is on and with no signal, the total power consumption of the plate amp is 8W. In other words, it still consume 6W in stand-by mode. Out of 6W, 2W is from transformer core loss and 4W is from pre-amp and control circuit. With our previous amps featuring auto-on function, I received a couple of feedback about auto-on function not sensitive enough in their setup. As a solution, I have always recommended to put them in on mode.

I have recently worked on a class D amp and noticed its power consumption is higher when the amp is ON and no signal present. In my particular case, it is 18W. If I were to adapt it for servo, an auto-on function is a must. Hopefully this will settle the concern that there is no more auto on switch in our PEQ2 amps.

DonH50 03-01-2010 10:49 PM

My other amps are turned on by a trigger circuit from the AVR; is that a possibility? I understand it won't make much power difference but my area (out in the sticks) has power problems so I tend to keep everything on standby or off, didn't think about the subs not auto-off'ing. Not a huge deal, just need to remember to turn them off, and set them where it's not too hard to do so.

That is, my two new F12 subs, just got the shipping notice and am anxiously awaiting their arrival, thank you very much! My old custom-designed servo subwoofer died an untimely death in a move (movers sent something through the speaker, big hole in the cone, ripped surround, and tweaked the VC so it's one dead puppy ) and the replacement I got just isn't cutting it... For the record, seeing the company engineer post here is one of the reasons I went for them. Got to keep helping out my hairy-knuckled brethren...

panzer 03-02-2010 05:26 AM

Sorry for my ignorance, but does it mean with the sub no longer having a auto on feature, your only 2 options are to leave it on or manually turn it on and off ?

Rythmik 03-02-2010 06:58 AM

Quote:
Originally Posted by DonH50 View Post

My other amps are turned on by a trigger circuit from the AVR; is that a possibility? I understand it won't make much power difference but my area (out in the sticks) has power problems so I tend to keep everything on standby or off, didn't think about the subs not auto-off'ing. Not a huge deal, just need to remember to turn them off, and set them where it's not too hard to do so.

That is, my two new F12 subs, just got the shipping notice and am anxiously awaiting their arrival, thank you very much! My old custom-designed servo subwoofer died an untimely death in a move (movers sent something through the speaker, big hole in the cone, ripped surround, and tweaked the VC so it's one dead puppy ) and the replacement I got just isn't cutting it... For the record, seeing the company engineer post here is one of the reasons I went for them. Got to keep helping out my hairy-knuckled brethren...


It is still not too late. If auto-on is a must, we can ship the subs with A370PEQ amp. But the new A370PEQ2 does not have auto-on feature anymore. It is either on or off.

The 24V trigger is a common pro audio feature. We haven't implemented that. Most plate amps do not have that. It is more comonly seen in rack mount amps.


That aside, if the power noise is from ground loop, my experience is that it won't go away by putting the amp in stand-by with our amplifier. I clearly remember this as I have one customer with hum noise issue even when the sub is in standby mode. He later temporarily resolved it with a cheater plug.

This brings up another issue. Whenever there is a ground loop problem, cheater plug is really a temporary fix.

Rythmik 03-02-2010 07:44 AM

Quote:
Originally Posted by panzer View Post

Sorry for my ignorance, but does it mean with the sub no longer having a auto on feature, your only 2 options are to leave it on or manually turn it on and off ?

You are correct. BTW, I am eager to hear the usage feedback on limiter. If only a few customers can hear the sonic difference from a limiter at moderate level, then we should keep limiter on all the time and bring back the auto on feature. It is the customer feedback that guides future product development.

atroder 03-02-2010 08:26 AM

Brian, is the intent of the limiter to limit distortion at higher levels, but in doing so it introduces sonic effects of it own? Please elaborate.

sanjaygolf 03-02-2010 10:46 AM

Quote:
Originally Posted by Rythmik View Post

In addition, the decision between 12" sub and 15" subs should also depend on the woofer size in the front speakers. If the front speakers also have 6-1/2" woofer or bigger, there is no point of using 12" subs.

Is this a practice that should always be applied or are there circumstances where a 12" sub mated with a 6 1/2" mains would be better than a similarly equivalent 15"?

vantagesc 03-02-2010 10:55 AM

Brian, is there any difference in output when the new DS1510 driver is installed in an F15 box vs. E15 box?

panzer 03-02-2010 01:33 PM

I am very disapointed, I was about to order 2 se 12's from ascend to go with my new songtowers, with no auto on , it is a deal killer, thanks

porksoda 03-02-2010 01:37 PM

Quote:
Originally Posted by panzer View Post

I am very disapointed, I was about to order 2 se 12's from ascend to go with my new songtowers, with no auto on , it is a deal killer, thanks

whats the "deal killer" here?

stevec325 03-02-2010 03:39 PM

Quote:
Originally Posted by Rythmik View Post

You are correct. BTW, I am eager to hear the usage feedback on limiter. If only a few customers can hear the sonic difference from a limiter at moderate level, then we should keep limiter on all the time and bring back the auto on feature. It is the customer feedback that guides future product development.

Brian,

Is it possible to enable auto-on via a jumper on the inside of the amp?

From your description, it sounds like you are just using the "switch" to control the limiter function. If so, is the circuitry still inside the amp to configure for auto-on?

Many of us would probably be comfortable with making an internal connection on the PEQ2 amp to select auto-on.

If that is possible, then we may be able to solve the problem for the few users that want auto-on.

Tank45 03-02-2010 04:35 PM

I spoke with Brian today and determined that I will be ordering a 15 with the 600w amp at the end of the month when they come available. One question though - from the post speaking of the "E" or "F" enclosures... will they differ tonally due to the reduced size of the "E"? Granted, it isn't that much of a size difference.

ddgtr 03-02-2010 11:09 PM

Does anyone know where the Rythmic subs are made?

Also, when ordering, do you have to specifically ask for the balanced version? I can't tell from the pictures on their site.

Thanks

Rythmik 03-03-2010 06:37 AM

Quote:
Originally Posted by atroder View Post

Brian, is the intent of the limiter to limit distortion at higher levels, but in doing so it introduces sonic effects of it own? Please elaborate.

The purpose of limiter is to keep the output under power rail limit so that the amplifier clipping noise is less audible. This is more important for F12 than F15. However, its sonic coloration at low level and moderate level is my concern.

Rythmik 03-03-2010 06:44 AM

Quote:
Originally Posted by sanjaygolf View Post

Is this a practice that should always be applied or are there circumstances where a 12" sub mated with a 6 1/2" mains would be better than a similarly equivalent 15"?

The intuitive thinking is to think of subwoofer as one way of your multi-way system. Therefore reasonable size selection is a good starting point. If due to room issue, one can only get best results by cross-over front higher (for instance at 80hz), then 12" is a better fit.

On the other hand, 6-1/2" woofers allow us to cross over at a lower frequency and lower frequency has longer wave length and therefore, smaller phase shift with the same physical distance, and that makes the phase alignement more robust and less sensitive to location. For instance, the wavelength at 80hz is 12ft. 6 ft will give us 180 degrees phase shift. On the other hand, the wavelength at 60hz is 16ft, it takes 8 ft to gives us 180 degrees phase shift.

Rythmik 03-03-2010 06:51 AM

Quote:
Originally Posted by vantagesc View Post

Brian, is there any difference in output when the new DS1510 driver is installed in an F15 box vs. E15 box?

Smaller enclosure would have a bit less output below say 25hz. But the difference is very small (less than 1db). Above 25hz, the output between the F15 and E15 is the same.

Rythmik 03-03-2010 06:57 AM

Quote:
Originally Posted by stevec325 View Post

Brian,

Is it possible to enable auto-on via a jumper on the inside of the amp?

From your description, it sounds like you are just using the "switch" to control the limiter function. If so, is the circuitry still inside the amp to configure for auto-on?

Many of us would probably be comfortable with making an internal connection on the PEQ2 amp to select auto-on.

If that is possible, then we may be able to solve the problem for the few users that want auto-on.

If one really feel auto-on is so important, I would recommend to go with A370PEQ. We can still install A370PEQ amp to any of our subwoofers and A370PEQ has been out there for almost 3 years now and the function it offers is very good. I don't like to idea of offering different customization for the same model.

Rythmik 03-03-2010 07:14 AM

Quote:
Originally Posted by panzer View Post

I am very disapointed, I was about to order 2 se 12's from ascend to go with my new songtowers, with no auto on , it is a deal killer, thanks

I understand your disappointment. However, my priority is to get the best sound quality to the customers. For me, a switch to defeat the limiter is more important. Did I get my priority wrong?

Rythmik 03-03-2010 07:34 AM

Quote:
Originally Posted by ddgtr View Post

Does anyone know where the Rythmic subs are made?

Also, when ordering, do you have to specifically ask for the balanced version? I can't tell from the pictures on their site.

Thanks

They are made in China and the subs are assembled here. It has been like this for two years. I supply many custom parts to my amplifier supplier. So even though my supplier makes amplifiers for M&K and EP*K, our amplifiers do not sound like theirs at all. Our drivers used to be from TC Sounds, but they no longer exist. Even when our drivers were made by TC, almost all components were imported from China. That is why we are able to main the look of our DS1200 drivers same as our DS12 drivers. Our DS1510 has a cone that is same as our older DS15 driver (made by TC) except with even bigger motor. For all of our 15" drivers, the voice coils are still made in Florida by precision econowind and then air ship to China. All other parts can be rightly called "commodity", but not voice coil.

EDIT: I missed the 2nd question: To order with XLR, please first let me know and then put "XLR" in the note field when ordering via on-line system.

cschang 03-03-2010 09:39 AM

1 Attachment(s)
Quote:
Originally Posted by Rythmik View Post

I understand your disappointment. However, my priority is to get the best sound quality to the customers. For me, a switch to defeat the limiter is more important. Did I get my priority wrong?

I don't think so.

Improving on sound quality is never a bad thing.

David Barteaux 03-03-2010 09:58 AM

Knowing thet the crossover is not defeatable, explain to me the best way to set the crossover and other settings to the D-15SE. I have THX Ultra reciever and Klipsch THX Ultra2 speakers. I want the best blend for my speakers utilizing the THX reccomended spec of 80Hz. My room is approx 2100 cu ft.

Would an HSU ULS-15 be a better choice for THX speakers?

Thanks.

Rythmik 03-03-2010 10:18 AM

Quote:
Originally Posted by David Barteaux View Post

Knowing thet the crossover is not defeatable, explain to me the best way to set the crossover and other settings to the D-15SE. I have THX Ultra reciever and Klipsch THX Ultra2 speakers. I want the best blend for my speakers utilizing the THX reccomended spec of 80Hz. My room is approx 2100 cu ft.

Would an HSU ULS-15 be a better choice for THX speakers?

Thanks.

There has been a lot of discussion about how a flat upper end extension is important. Actually it is not. In many many cases, having a flat upper end extension is actually a bad things. Why? No textbooks say so! That is because one cannot make good products if he strictly follows textbook.

For subwoofers, we need to deal with cone break-up as well as enclosures internal reflection and coloration. Both of them takes place at the upper end of frequency response. Having a less roll-off at upper end exposes those problems more easily.

Our phase integration web page explains very well that the key to smooth integration is phase alignment. Not the flat upper end extension. http://www.rythmikaudio.com/phase.html. So I would say it is as easy as set it up and playing with delay time adjustment.

Fatawan 03-03-2010 10:31 AM

Brian:

Could the new 600W amp be used to drive two of the older DS1500 drivers? I was thinking of a dual opposed box with a single amp, like an Epik Empire or Seaton Submersive.

vantagesc 03-03-2010 10:35 AM

Can't stress Brian's phase comments enough.

You don't have to get phase perfect, but at some point it can turn the normally tight sounding sub into something that sounds a bit flabby. I think this is because bass notes often have harmonics that reach very high in frequency, so if your sub is not playing in concert with your mains, things fall apart.

David Barteaux 03-03-2010 10:48 AM

Quote:
Originally Posted by Rythmik View Post

There has been a lot of discussion about how a flat upper end extension is important. Actually it is not. In many many cases, having a flat upper end extension is actually a bad things. Why? No textbooks say so! That is because one cannot make good products if he strictly follows textbook.

For subwoofers, we need to deal with cone break-up as well as enclosures internal reflection and coloration. Both of them takes place at the upper end of frequency response. Having a less roll-off at upper end exposes those problems more easily.

Our phase integration web page explains very well that the key to smooth integration is phase alignment. Not the flat upper end extension. http://http://www.rythmikaudio.com/phase.html. So I would say it is as easy as set it up and playing with delay time adjustment.

All good reading, but can u give me the initial settings for vented THX speakers?

Rythmik 03-03-2010 11:05 AM

Quote:
Originally Posted by David Barteaux View Post

All good reading, but can u give me the initial settings for vented THX speakers?

Not a problem. My experience is for a 4-1/2" vented front, one needs to add 4 or 5 ft of distance to subs in addition to physical distance. For 6-1/2" vented front, one would need only 1-2 if the xover is set to 80hz.

Rythmik 03-03-2010 11:07 AM

Quote:
Originally Posted by Fatawan View Post

Brian:

Could the new 600W amp be used to drive two of the older DS1500 drivers? I was thinking of a dual opposed box with a single amp, like an Epik Empire or Seaton Submersive.

Not at this moment. It will be one day soon. I sent you an PM.

andy133 03-03-2010 11:11 AM

Quote:
Originally Posted by Rythmik View Post

Not at this moment. It will be one day soon. I sent you an PM.

Similar question here. For a submersive-like design with Rythmik drivers should I use two 370 amps?

jpmst3 03-03-2010 11:15 AM

Quote:
Originally Posted by Fatawan View Post

Brian:

Could the new 600W amp be used to drive two of the older DS1500 drivers? I was thinking of a dual opposed box with a single amp, like an Epik Empire or Seaton Submersive.

That would be a sweet design. The performance of the Empire (at least), but much improved SQ.

Rythmik 03-03-2010 11:25 AM

Quote:
Originally Posted by andy133 View Post

Similar question here. For a submersive-like design with Rythmik drivers should I use two 370 amps?

At this moment, I would say so. However, that guarantees you to get 6db increase in output even though you only increase the power by 3db. It sounds like we are getting 3db freebie. The key is the enclosure size has also double when one uses dual driver. If the total enclosure size is kept the same, we are back to square one and only improve the output by 3db.

BTW, you guys keep coming up with new idea I cannot keep up with . I have in my hand FV15, TH, class D servo, ... not to mention I still owe Rick some answers about 8" or 10" servo... help!

vantagesc 03-03-2010 11:32 AM

David, for the crossover, I believe you simply set the crossover slope switch to EXT 12 and turn the crossover knob to the maximum. Not sure if that second step is necessary.

DonH50 03-03-2010 01:15 PM

Flat upper extension on a sub? Hmmm... I have always found the problem to be with directionality as the frequency gets much north of 50 - 100 Hz. In controlled test years ago it was easy to localize a sub at around 100 - 120 Hz, almost impossible at 50 Hz, in between a gray area. With satellites crossing over around 80 - 100 Hz, there was enough energy in the upper bass to me that I felt dual subs were needed. My main speakers go low enough that isn't an issue, but I like the idea of duals for various other reasons. YMMV.

Given the slight power difference (less than a nightlight), auto-on only matters to me if it's needed to control turn-on transients (thumps). Not a problem I have seen in the past decade or two, at least for anything I have tried. My old vintage (ARC SP-3) tube preamp does need some warm-up time, however, if you don't want to lose an amp, and/or maybe a speaker. Trust me on this... As it stands, the limiter sounds like a good idea to me. I doubt it will have any audible impact in the subwoofer range (higher, yes), and it sounds like an idea that will save a lot of speakers and EARS! Hearing damage is not a good thing.

I would be glad to post what I hear (which of course may not be anything like what you hear) from an A-B with the limiter on and off once my new subs arrive. For equipment I am using Magnepan MG-IIIa's driven by an emotiva XPA-3 for my mains, from a Sony ES3400 receiver, and with an Infinity center (driven by the emotiva) and Mirage surrounds (driven by the Sony). However, by this weekend I should have the new subs plus a new center and surrounds from Magnepan so it will be quite an experience. My first major system upgrades in years.

New toys! - Don

p.s. Not sure how ground loops snuck into Brian's reply to me. I have many years' experience doing live sound and sound installs though little recently (not my day job) and ground loops can be terrible things. Despite the "quick fix" they often provide, a cheater is my last resort for many reasons, not the least of which is that they can be dangerous. Besides the obvious shock potential, my neck of the woods is very dry (CO front range) and static is a big problem. I want the ESD going to a good ground, not inside my components...

mcreyn 03-03-2010 01:46 PM

Quote:
Originally Posted by Rythmik View Post

BTW, you guys keep coming up with new idea I cannot keep up with . I have in my hand FV15, TH, class D servo, ... not to mention I still owe Rick some answers about 8" or 10" servo... help!

I will throw another out there. Have pre-made enclosures for sale so people can mix and match, like me who wants a F12G but in the downward firing box design you show on your website.


Quote:
Originally Posted by DonH50 View Post

Flat upper extension on a sub? Hmmm... I have always found the problem to be with directionality as the frequency gets much north of 50 - 100 Hz. In controlled test years ago it was easy to localize a sub at around 100 - 120 Hz, almost impossible at 50 Hz, in between a gray area. With satellites crossing over around 80 - 100 Hz, there was enough energy in the upper bass to me that I felt dual subs were needed. My main speakers go low enough that isn't an issue, but I like the idea of duals for various other reasons. YMMV.

I have run stereo subs for years (Velodyne ULD-12s). There is a definite benefit to stereo subs. I think it is two fold, first it helps flatten out room peaks and nodes, second, it preserves out of phase bass information in a recording that would otherwise be summed out in a mono subwoofer.

In regards to a subwoofer having flat upper extension, this is very important in my book. Assuming a 12db octave crossover at 80 hz, the subwoofer is only down 12 db's at 160hz. Any nonlinearity in that range could easily effect the sound.

Rythmik 03-03-2010 02:27 PM

Quote:
Originally Posted by jpmst3 View Post

That would be a sweet design. The performance of the Empire (at least), but much improved SQ.

I have offered dual 12" drivers as kits for some time now. I have only limited success. To give it another shot, we will have 8ohms 15" driver (in both black and silver cone color) coming in at the end of this month. Hopefully that is the ticket. They will work with our H600 servo amp. All of them are based on aluminum cones.

FlavioSupra 03-03-2010 02:32 PM

Quote:
Originally Posted by Rythmik View Post

I have offered dual 12" drivers as kits for some time now. I have only limited success. To give it another shot, we will have 8ohms 15" driver (in both black and silver cone color) coming in at the end of this month. Hopefully that is the ticket. They will work with our H600 servo amp. All of them are based on aluminum cones.

How much would a dual 15"/H600 servo amp kit cost?

DonH50 03-03-2010 03:25 PM

Quote:
Originally Posted by mcreyn View Post

In regards to a subwoofer having flat upper extension, this is very important in my book. Assuming a 12db octave crossover at 80 hz, the subwoofer is only down 12 db's at 160hz. Any nonlinearity in that range could easily effect the sound.

We agree! That's why I made the comment about satellites in my post. However, I cross over around 40 Hz, so an octave away at 80 Hz the sound is about half loudness (more than 10 dB down) as you say (with a second-order LPF; my previous system used 3rd-order so 18dB/octave) and relatively non-localized. At 80 Hz crossover, I would not be happy without dual subs -- too much energy left up where it can be heard and localized. With my current mains, I can cross over low enough to minimize the issue (though I still ordered two subs).

The new variable for me is HT's LFE channel, which apparently includes content to 120 Hz in the sub channel. One of the reasons I decided to run two subs; I'm still debating whether to hook them up in parallel with the mains (creating extra-full-range mains and telling the AVR "no sub") or in parallel from the LFE output (opinions welcome, though probably should be in another thread). I hope to try both.

I was asked regarding the higher-power amps (shouldn't have, as a newbie and unknown voice here, but one was curious why I didn't wait). In my relatively small room I don't need the extra output, especially with two subs, and damping factor (speaker control, the -- or at least my -- other reason for bigger amps) is a non-issue with a servo loop. It takes twice the power to generate a 3 dB loudness increase, just noticeable to most of us listening to musical (or movie) source material. Twice as loud, 10 dB, 10x the power. However, the ratio of average to peak power in music is around 17 dB, or about 50x in power, so it does pay to have some overhead in your amps. But, the difference between 370 W and 600 W is not all that great in the real world, where your average power might be just a few watts. And with servo subs in relatively small boxes, great gobs of power should not be required (let the rebuttals begin).

All of which is a nice rationalization for simple impatience -- I couldn't wait to get my new system set up!

Tank45 03-03-2010 06:57 PM

Just read that phase document Brian referenced off of his page. Going to have to read it again and get my brain wrapped around it a little better before my F-15 (600w) gets here - next week hopefully.

Rythmik 03-03-2010 11:11 PM

Quote:
Originally Posted by FlavioSupra View Post

How much would a dual 15"/H600 servo amp kit cost?

It would be $799 tentatively.

BTW, we now have a distributor in Taiwan. We can offer surface shipping from Taiwan to Europe and one can save quite a bit. For instance, the surface shipping of DS1200 kit and DS1501 kit is about $75. Several European customers have complained about the air shipping cost. Unfortunately US postal service does not offer surface shipping anymore. but Taiwan postal office still does. Currently the kits that can ship from Taiwan is limited to DS1200 (black cone), DS1501 (black cone) and DS1500 (silver cone) only.

Fatawan 03-04-2010 05:50 AM

Quote:
Originally Posted by Rythmik View Post

It would be $799 tentatively.

What would the output be for this combo compared to a single 15 or single 12? What size enclosure would be required? Would the drivers be black or silver?

Rythmik 03-04-2010 08:10 AM

Quote:
Originally Posted by Fatawan View Post

What would the output be for this combo compared to a single 15 or single 12? What size enclosure would be required? Would the drivers be black or silver?

If we keep the enclosure size of 3 cu ft per driver, or 6 cu ft total, one can get 5db more output than a single 15" driven by 370WRMS. The reason is each driver gets 300WRMS power from the amp and we know there is 1db less output when we move from 370WRMS to 300WRMS, but the output doubles at 6db with 600WRMS and two drivers. So the net result is 6db -1db=5db. If we reduce the enclosure size, then we get less output below 28hz or so. The smaller enclosure we have, the less output we get.

inthepit 03-05-2010 11:34 AM

Just got my F12 today. Looks awesome. My question is, I don't know how to connect the LFE output from my Onkyo 805 to the L/R inputs on the F12. Should I just get a Y splitter and connect to L/R or just put the LFE into one of the inputs?

jpmst3 03-05-2010 11:37 AM

Quote:
Originally Posted by Rythmik View Post

I have offered dual 12" drivers as kits for some time now. I have only limited success. To give it another shot, we will have 8ohms 15" driver (in both black and silver cone color) coming in at the end of this month. Hopefully that is the ticket. They will work with our H600 servo amp. All of them are based on aluminum cones.

Ya, I had forgotten about the 12s, but 15s would be even better!

monomer 03-05-2010 02:41 PM

Quote:
Originally Posted by inthepit View Post

Just got my F12 today. Looks awesome. My question is, I don't know how to connect the LFE output from my Onkyo 805 to the L/R inputs on the F12. Should I just get a Y splitter and connect to L/R or just put the LFE into one of the inputs?

Yes either way would be perfectly fine, just remember to adjust the gain control on the sub appropriately (so the Onkyo's calibration level ends up around in the -5dB to 5dB range)... And congratulations on your purchase of a great sub.

fyzziks 03-05-2010 03:22 PM

Quote:
Originally Posted by Rythmik View Post

Our phase integration web page explains very well that the key to smooth integration is phase alignment. Not the flat upper end extension. http://http://www.rythmikaudio.com/phase.html. So I would say it is as easy as set it up and playing with delay time adjustment.

I would like to read your ideas on phase coherence, but the link above seems to not work for me.

sdurani 03-05-2010 03:24 PM

Quote:
Originally Posted by fyzziks View Post

I would like to read your ideas on phase coherence, but the link above seems to not work for me.

Try this one: http://www.rythmikaudio.com/phase1.html

DonH50 03-05-2010 09:22 PM

Thanks Sanjay. Now, is there any way to download that as a PDF (or whatever) for a clean print-out? Maybe I'm blind, but I only saw the three-page online version...

This is vital now that I have my subs sitting on the floor ready to go! - Don

DonH50 03-06-2010 01:33 AM

OK, so I read the article, and it makes a lot of sense. The concept that the phase must align around the crossover to prevent cancellation (and thus a dip in response) is clear (aligning multiple drivers in a speaker, or PA system, is something I am familiar with). However, is there a chart somewhere that we can find the phase of our speaker, assuming we can't get it from the manufacturer (mine are fairly old though still nice)? Otherwise, it seems to me we still have to adjust and listen (or measure) to optimize the phase (delay) control. I suppose the easiest way might be with test tones around the crossover frequency and an SPL meter? Just adjust the phase for maximum output?

Curious - Don

Rythmik 03-06-2010 08:02 AM

Quote:
Originally Posted by DonH50 View Post

However, is there a chart somewhere that we can find the phase of our speaker, assuming we can't get it from the manufacturer (mine are fairly old though still nice)? Otherwise, it seems to me we still have to adjust and listen (or measure) to optimize the phase (delay) control. I suppose the easiest way might be with test tones around the crossover frequency and an SPL meter? Just adjust the phase for maximum output?

Curious - Don

Let me first get to your question. The page actually gives us some examples we can extrapolate. Once we understand the root causes of phase shift in front speakers, one can make pretty good guesstimate about the distance one should set. If software like Audyssey comes back with a very different number, which one should you trust? It is the one based on physics.

So. the biggest factor in phase is whether the front is ported or sealed. Ported fronts have more phase shift and therefore need more delay time adjustment (4th order roll-off vs 2nd order roll-off). At corner frequencies, their phase shift is 180 degrees and 90 degrees, respectively. The second factor is the woofer size. 4-1/2" and 6-1/2" are different and woofer/cabinet sizes affects natural extension (or roll-off corner frequency) which in turn, determines the phase shift. It is just as predictable as bode plots. Although one still needs to tweak in the final adjustment, but the range should really be within +/- 2 ft.


BTW, the manufacturers do not even publish phase response for subwoofers in which phase response is really important. In Illkka's test, it showed our DS12 has the lowest group delay among all subs he has tested. Correct me if I am wrong here. Even Illka's test can only be used as comparative study, not as absolute reading, in particular towards the bottom end because all microphone needs calibration in both amplitude and phase (and yet microphone calibration file only has amplitude correction, where are the phase correction data? ). At frequencies where microphone measurement is no longer reliable, what should we use? You may have guessed it.

DonH50 03-06-2010 09:51 AM

Thanks Brian -- I'm off to pick up a new SPL meter this morning. My cheap old hand-held spectrum analyzer isn't the right tool for this, and the company I work for now does not have audio test gear (when your sub goes up into the GHz range, I can test it! ).

I think the most important thing with group delay is that it's as flat as possible, but yeah if it's pretty far off between sub and mains I can see where there'll be problems. Especially if the sub lags the mains -- hard to reverse time! I like the idea of playing with the distance settings, though my new receiver (Pioneer SC-27, two weeks away) should balance things across frequency.

In response to your first answer last (follow that? not sure I did...) my mains are planar bipolars -- Magnepan MG-IIIa's -- so phasing gets a little complicated. The good news is that they are very linear speakers (good impulse response); the bad news is that the room's influence is huge on the wavefront at the listening position due to the reflected waves. To further complicate things, there's an inversion (180 deg shift) in the system to the mains (not sure where it's at, just that the AVR's cal routine caught it).

Excellent point on the microphones -- I have a nice (and pricey!) earthworks measurement mic, but as I recall you are right that only an amplitude calibration curve is provided, no phase data. OTOH, you'd need to calibrate the system through the pre and whatever anyway, for amplitude and phase, so having just the mic amplitude response is not perfect.

One final question/comment for you or whomever: Do you suggest spikes under the subs? My media room is in the basement so has concrete under the carpet, but there's a fairly new (thick) carpet and pad on top. I realize the weight of the sub will flatten it down, just curious. I never would have believe Doppler effects matter for audio speakers, but some listening and measurements convinced me otherwise many years ago.

Thanks much -- the new subs get turned on today! - Don

Rythmik 03-06-2010 04:38 PM

Quote:
Originally Posted by DonH50 View Post

In response to your first answer last (follow that? not sure I did...) my mains are planar bipolars -- Magnepan MG-IIIa's -- so phasing gets a little complicated. The good news is that they are very linear speakers (good impulse response); the bad news is that the room's influence is huge on the wavefront at the listening position due to the reflected waves. To further complicate things, there's an inversion (180 deg shift) in the system to the mains (not sure where it's at, just that the AVR's cal routine caught it).

In the ideal case, the dipole has an additional 6db/oct roll-off with corner frequency determined by the baffle width. Other than that, it is same 2nd order roll-off as the sealed speakers. So it is 3rd order, between 2nd order sealed woofer and 4th order vented woofer. In your case, the corner frequency (where it has additional 45 degrees shift) should be above 200hz. So when it goes down to 80hz, we should have close to 90 degrees phase shift. I would treat it as vented. There is a difference between 180 deg shift and inversion. The 180 deg shift can be from a high pass filter just like a vented subwoofer at the corner frequency of roll-off. But if we conclude the signal has been inverted, that would be incorrect. I normally look at the phase plot as a whole to conclude if the signal has been inverted.

Quote:


One final question/comment for you or whomever: Do you suggest spikes under the subs? My media room is in the basement so has concrete under the carpet, but there's a fairly new (thick) carpet and pad on top. I realize the weight of the sub will flatten it down, just curious. I never would have believe Doppler effects matter for audio speakers, but some listening and measurements convinced me otherwise many years ago.

You can use spikes over carpet. I don't recommend spikes over hard floors. The improvement from spike is very subtle with our subwoofers.

DonH50 03-06-2010 11:15 PM

Thanks Brian -- making me think, hurts! Too long since my grad acoustics classes...

The LF corner (per Magnepan) is around 35 Hz, but you are relating the shift to the baffle size rather than the LF corner (curious, I am trying to learn this stuff)? Makes some sense to me. I was planning to run the subs in parallel with the main amp (not using the AVR's sub output) and cross over ~40 Hz, around the Maggie's LF corner, with the steep roll-off (to limit bleed into the mains), and then check the response. I started on that today but got sidetracked and haven't finished yet. And, I really wish I had an audio VNA to generate phase! With a sweeper, natch, instead of test tones, an SPL meter, and hand recording. My old (old, old) cheapie handheld SA is not sensitive enough. All I can do now is play with the amplitude, a relatively hit-and-miss proposition.

My general plan was/is to test the sub around 25 - 30 Hz and match the amplitude to the mains at some midband frequency, maybe 400 Hz. That is, match the amplitude where the mains are fairly rolled off to the amplitude of the mains in their lower midband. Then, measure at the crossover point (around 40 Hz) and adjust the delay to match amplitudes at that point. Pretty rough, but all I've thought of for the moment. I value your advice as a sanity check on where the delay ends up.

I also need to revisit the inversion. The AVR (a Sony 3400ES) simply said the mains were "inverted" during its cal cycle and suggested I flip the speaker wires to correct (I did and got rid of the warning.) The AVR could well be reading them wrong (due to the reflections etc.), or the amp could be inverting (have not checked). I assumed a true inversion, not a 180 phase shift, thanks for keeping me honest! The amplitude rises pretty monotonically as I increase the delay, making me suspect the AVR lied and I need to flip the wires back.

I have also picked up some noise/hum, probably due to the extra 10' lines from the splitter hanging on the back of the AVR now (one set to the mains, the other to the subs). It might be unrelated, e.g. it's been there and I haven't noticed before. Turning the subs on and off has a slight impact but they are clearly not the cause. I may have to get better-shielded cable than the $10 Radio Shack specials I was able to scrounge today. I also need to revisit the rat's nest behind the AVR and pay more attention to cable dressage -- stereo was a lot simpler, and I didn't have digital and video feeds running around the audio cables!

My experience in the primordial past was that spiking the mains sometimes helped, but had virtually no impact on the sub, probably due to its limited bandwidth. I was curious as to your thoughts, thank you!

The good news is that even with the very limited testing I have done so far your subs (mine now!) blow away the Infinity PS212 I had been using since my old servo sub died, and do indeed seem to match well with the Magnepans, speakers traditionally very intolerant of lesser subs. Hopefully I'll be able to dial things in tomorrow.

Thanks again,
Don

rpr13 03-07-2010 11:03 AM

The Rythmik website curreently lists the D15SE sub as being on back order, with a reference to the A370PEQ2 amp. Is this a new amp? If so, what's different?

monomer 03-07-2010 11:09 AM

Quote:
Originally Posted by rpr13 View Post

The Rythmik website curreently lists the D15SE sub as being on back order, with a reference to the A370PEQ2 amp. Is this a new amp? If so, what's different?

Its actually been discussed in some detail within this thread in a couple of different postings... go back and read posting #122 in this thread, you should find it helpful.

DJLEC 03-07-2010 11:15 AM

Still hoping to get an answer between the F12 or F15. I even left a message for Brian but no return call.

Which would be the best size for a 22' L x 13' W x 10' H (Average since it is peaked) which equals 2,860 cubic foot sealed room with one doorway.

I am 100% HT and presently using two REL Storm III subs. They have a 10" Driver with a 150 W to 300W peak amp. As you can see in the attached picture I now have them co-located. This is the best spot in the room at present.

I can have it fire the short width of the room adjacent to the couch end or fire from the corner towards the couch.

Would like to have one sub in the corner if possible.
LL

monomer 03-07-2010 11:30 AM

Well I had a single F12 in a sealed ~2200Cu-ft room for a short while this past summer and found it more than capable of pressurizing the room for movies... since then I've purchased another F12 and am now running duals (one on each side of the room). The F15 will provide at least another 3dB over the F12 so you really couldn't go wrong since the price difference is really quite minimal. If you want my opinion, I would suggest you go with the F15 if you intend to cross over below 80Hz... if you are intending to cross higher, I would suggest you continue to seek Brian's input... but might want to consider two F12s (w/ GR drivers).

mcreyn 03-07-2010 11:38 AM

Quote:
Originally Posted by DJLEC View Post

Still hoping to get an answer between the F12 or F15.

Which would be the best size for a 22' L x 13' W x 10' H (Average since it is peaked) which equals 2,860 cubic foot sealed room with one doorway.

I am 100% HT and presently using two REL Storm III subs.

Would like to have one sub in the corner if possible.

My two cents, especially given you are using it for home theater, the 15" is a no brainer given the small additional cost.

The Storm V when tested by Ilkka was putting out 96 db at 40 hz, 92 db at 30hz, and 85 db at 20 hz. So using two co-located would give 102 db at 40hz, 98 db at 30hz, and 91 db at 20hz. The 12" Rythmik sub tested in the same manner by Ilkka gave 105 db at 40hz, 104db at 30hz, and 96 db at 20 hz. By going with the Rythmik 12" you will see anywhere from a 3-6db increase in output capability over you current setup (same as buying two more REL Storm's). This is a decent increase and probably fine if you were never stressing the output of the REL's. Going to the 15" will give you another 3-5 db's across the board (more than 6 dbs over your current system as as much as 12 db), a nice increase in headroom for home theater.

cschang 03-07-2010 01:21 PM

1 Attachment(s)
Quote:
Originally Posted by monomer View Post

...I would suggest you go with the F15 if you intend to cross over below 80Hz... if you are intending to cross higher, I would suggest you continue to seek Brian's input... but might want to consider two F12 (w/ GR drivers).

Apparently with the new PEQ2 amps, crossing over higher than 80hz isn't a problem.

cschang 03-07-2010 01:29 PM

1 Attachment(s)
Quote:
Originally Posted by rpr13 View Post

The Rythmik website curreently lists the D15SE sub as being on back order, with a reference to the A370PEQ2 amp. Is this a new amp? If so, what's different?

The difference in the PEQ2 amp is in an earlier post:
https://www.avsforum.com/avs-vb/showt...6#post18215646

DJLEC 03-07-2010 08:52 PM

I wish to thank you for such a great response.

This helps me tremendously in my decision.


Quote:
Originally Posted by mcreyn View Post

My two cents, especially given you are using it for home theater, the 15" is a no brainer given the small additional cost.

The Storm V when tested by Ilkka was putting out 96 db at 40 hz, 92 db at 30hz, and 85 db at 20 hz. So using two co-located would give 102 db at 40hz, 98 db at 30hz, and 91 db at 20hz. The 12" Rythmik sub tested in the same manner by Ilkka gave 105 db at 40hz, 104db at 30hz, and 96 db at 20 hz. By going with the Rythmik 12" you will see anywhere from a 3-6db increase in output capability over you current setup (same as buying two more REL Storm's). This is a decent increase and probably fine if you were never stressing the output of the REL's. Going to the 15" will give you another 3-5 db's across the board (more than 6 dbs over your current system as as much as 12 db), a nice increase in headroom for home theater.


DonH50 03-07-2010 11:38 PM

A quick follow-up to my posts after installing and a little listening to audio and video today, fwiwfm:

1. Calibrating with a test CD and SPL meter is painfully slow but revealing. Among the things revealed are that I need to get going on room treatment...

2. Putting the two 12" subs in parallel with my main speakers works just fine and the AVR appears to handle the set-up OK (I am not using the AVR's sub output, but tapping off the preamp outputs so the subs are driven as a stereo pair in parallel with the main L/R speakers). Except that...

3. I still have a bit of hum/noise that I think is cable-related. I have fairly long (10') cables from the AVR to the main L/R power amp, and another pair of long cables to the subwoofers. Line dress helped some but I am going to have to work on it a bit more. I did prove it is not the subwoofers themselves. Blue Jeans Cable is in my future...

4. Using the two Rythmik subs absolutely blows away the relatively inexpensive Infinity 12" sub I was using. The image is much better now, the bass deeper and much cleaner, and even after AVR cal (which ran the Infinity a little too "hot" for me) the sound is clean and the subs do not sound like separate speakers. The blend with my Maggies is very good, no mean feat. It has confirmed my long-ago experience that two subs are far better than one.

5. I tried flipping the limiter on and off and am not sure I ever heard a difference at moderate to fairly loud levels on a variety of musical source material. I meant to do it on the video, but got lost in the movie...

Bottom line: These subs are incredible! Having had good subwoofers in the past (commercial and custom) I knew my Infinity sub, while good enough paired with Infinity mains, was not working that great with my Magnepans. I was not prepared for just how much better the Rythmik subs sounded, and how large a jump in performance my whole system would take. I still have some tweaking to do, but I am very impressed. Kudos, Brian!

System:

Sony BDP350 BluRay player (CDs and BD; I have an Oppo 83 sitting in a box ready for installation)
Sony 3400ES AVR (processing and rear speakers' amp; I have a Pioneer SC-27 on the way)
emotiva XPA-3 (main L/R/C speakers' amp)
Magnepan MG-IIIa L/R mains
Magnepan CC3 center
Magnepan MC1 rear surrounds

Primary source material included a couple of old but familiar CDs: Flim and the BB's Tricycle, and Amanda McBroom/Lincoln Mayorga's Growing Up in Hollywood Town. I watched the new Star Trek movie for video. I used to have pretty good ears but have been out of the scene for a while, which perhaps only reinforces the improvement from the Rythmik subs since they (and the whole system) was so dramatically better to my aged ears.

To bed, gotta' work early tomorrow - Don

Tank45 03-08-2010 09:06 AM

A question. My F-15 should be here this week. The way my room is configured, I only have one power outlet behind the entertainment center where all my gear is. My Monster Power HTX3600 MK II power center gizmo is plugged into one of the receptacles and TV, BR, cable box, M&K sub, and receiver run thru it. My XPA-5 is plugged into the other receptacle as it is required to run it directly plugged into the wall. Should the F-15 be plugged into the power center or the wall directly? If it needs to be into the wall, then that will require a minimum 30 foot RCA cable run to the sub (it does not have XLRs nor does my receiver. Brian had indicated that I shouldn't use a longer run than 15' for the RCA cable. Any input? Thanks folks.

inthepit 03-08-2010 09:33 AM

Quote:
Originally Posted by Tank45 View Post

A question. My F-15 should be here this week. The way my room is configured, I only have one power outlet behind the entertainment center where all my gear is. My Monster Power HTX3600 MK II power center gizmo is plugged into one of the receptacles and TV, BR, cable box, M&K sub, and receiver run thru it. My XPA-5 is plugged into the other receptacle as it is required to run it directly plugged into the wall. Should the F-15 be plugged into the power center or the wall directly? If it needs to be into the wall, then that will require a minimum 30 foot RCA cable run to the sub (it does not have XLRs nor does my receiver. Brian had indicated that I shouldn't use a longer run than 15' for the RCA cable. Any input? Thanks folks.

I think power wise you can plug it in to whatever outlet you like. As for RCA cable this is what I'm using to connect my sub wirelessly to my AVR. It's a bit pricey relative to the price of the sub. I think there's a similar product out there for $99 or so, but I can't remember the name of it.

http://www.aperionaudio.com/catalog/...utions,84.aspx

Tank45 03-08-2010 10:16 AM

With that wireless, there is no signal loss/degradation at all?

inthepit 03-08-2010 10:31 AM

Quote:
Originally Posted by Tank45 View Post

With that wireless, there is no signal loss/degradation at all?

None that I could gather from the reviews. And there's a free 30day money back gaurantee. It's not any different than products like sonus streaming an entire audio signal over the airwaves.

http://www.aperionaudio.com/Products/Reviews.aspx

JimP 03-08-2010 01:15 PM

The other day I read a PDF from Bossobass where he maintained that you could not build a sub that's optomized for both music and home theater. That you have too make consessions for one or the other. He then goes on to state about using a musica sub with an ICBM for redirected bass and a home theater sub for the LFE channel.

Two question. Since the article is somewhat dated, is the basic premise still valid?

If it is, which of these subs would be the most musical? My mains are Atlantic Technology 8200 system with 8" woofers and my sub that will be used for the LFE channel is a SVS PB Ultra 13.

DonH50 03-08-2010 02:10 PM

Quote:
Originally Posted by Tank45 View Post

A question. My F-15 should be here this week. The way my room is configured, I only have one power outlet behind the entertainment center where all my gear is. My Monster Power HTX3600 MK II power center gizmo is plugged into one of the receptacles and TV, BR, cable box, M&K sub, and receiver run thru it. My XPA-5 is plugged into the other receptacle as it is required to run it directly plugged into the wall. Should the F-15 be plugged into the power center or the wall directly? If it needs to be into the wall, then that will require a minimum 30 foot RCA cable run to the sub (it does not have XLRs nor does my receiver. Brian had indicated that I shouldn't use a longer run than 15' for the RCA cable. Any input? Thanks folks.

I agree that the power strip can probably handle it, but you might want to add up the Watt ratings from the back panels and see how close to the limit you are getting. The XPA-5 draws 1500 W max and the plate on the back of my F12 (370PEQ2 amp, probably same as you are getting) says 750 W. That's already over the limit of a standard 15 Amp outlet (15A x 120V = 1800W max). That said, I had a dedicated 20A line run to our new media room to cover my bases, and with an XPA-3 and pair of F12's I'm over that limit as well (knew I should have gone for a 30A circuit but too late now; at least I have an extra standard 15A line for lights and such I could tap into). You will rarely if ever use all that power, and a brief transient will (almost always) stress but not pop a breaker so you are probably OK. I did not look up the specs on your power strip, but make sure it can handle the load; I'd probably use 50% power in the amps as a starting point. Why? No real good reason, just seems a reasonable place to be on average power with margin, and it's easy to divide by two. The add up the rest of the power (if the receiver has amps you can derate the back panel rating from that as well since you won't use all the power all the time, and with the emotiva virtually none in the AVR's amps).

HTH - Don

Tank45 03-08-2010 02:14 PM

Alrighty... I'll do the math. Thank you for that good info. Being a colorblind person - electrial stuff has never been my forte. Another reason to stay away from explosive ordinance disposal... "don't cut the blue wire"

DonH50 03-08-2010 02:25 PM

Quote:
Originally Posted by JimP View Post

The other day I read a PDF from Bossobass where he maintained that you could not build a sub that's optomized for both music and home theater. That you have too make consessions for one or the other. He then goes on to state about using a musica sub with an ICBM for redirected bass and a home theater sub for the LFE channel.

Two question. Since the article is somewhat dated, is the basic premise still valid?

While fairly new to the details of HT (though been a design engineer -- not audio -- for ages and used to be deeply embroiled into all things audiophile) this touches on a topic I have recently been researching. The LFE channel has fairly high frequency content, up to 120 Hz per the THX spec. That is well above what many (or maybe just me) consider the point at which you start to localize the subwoofer (i.e. high enough in frequency that it becomes directional). That's also pretty high if you have good full-range speakers for your L/R mains. Thus, a mono sub under your AVR's bass management is potentially going to "squash " the image at lower frequencies. Does it matter? Dunno' for you, but I can say that replacing my single sub with dual F12's sitting next to my mains solved an image problem I had, though this was partly due to the aforementioned high AVR crossover (again, THX standard is 80 Hz, leaving plenty of content in the sub even when I had full-range mains). So, I think it's still valid, as the required frequency response of the sub for HT is much higher than typical (or desired) for music.

In the past I had one sub centered and it worked OK. In my latest HT room I had to place the sub off to the side, compromising the image, and LFE wouldn't let me set the crossover low enough. Possible solutions are to set your sub up manually, if your receiver lets you do that well enough, or get a pair of subs, run them in parallel with the mains, and not use the AVR's sub output. If you have small mains, you'll need a HPF (high pass filter), either from the sub or externally, which could be a problem with an AVR (no place to break the loop and insert an external HPF without affecting the sub as well). Or, just get three subs, two near your mains for stereo, and a third for the LFE channel...

Can't help on the other question since I haven't heard them, sorry. - Don

laulau 03-08-2010 08:41 PM

Quote:
Originally Posted by DonH50 View Post

Primary source material included a couple of old but familiar CDs: Flim and the BB's Tricycle, ...

Ah yes, Flim and the BB's. "Tricycle", "Tunnel", "Neon" and "Big Notes" - some of the highest quality recordings ever, they're always part of my demo material. Of course, these days I use FLAC rips rather than touch my precious disks. My F12 really helps to hear all the glorious dynamic range in these recordings.


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