speakerman39

speakerman39

Audioholic Overlord
Folks, I have been doing a lot of reading on having multiple subs. There are differing opinions on this. For example, Dr. Earl Geddes highly recommends (3). On the other hand, Dr. Floyd Toole seems to recommend (4). I also found another Harmon Researcher that also recommends no more than (4).

We all know that duals smooth the in-room frequency response by reducing standing waves, and etc. Proper placement helps to reduce dips in the transient response as well. However, I am a bit dumbfounded as to go with (3) subs OR (4) subs.

Given that the SVS SB12-NSD's are still available for $399 each, I have given this question some serious thought. Actually, I got (2) of the SB12-NSD's for $766.08 shipped! Unfortunately, I could only apply (1) coupon and not (2) per account. That means, (2) more SB12-NSD's would cost me another $798! But, (1) more only $399 more. I admit I do NOT have enough experience to know whether or not going w/(3) OR w/(4) would be the better way to go. In other words, would (3) or even (4) SB12-NSD's make that much of a difference in my small ~1,350 Ft. ^3 room?

Here are the White Papers that I have been reading:

Dr. Geddes

https://drive.google.com/file/d/0BxgUOGOB5HbfR0JTRF9XZjkyUms/view?pli=1

https://drive.google.com/file/d/0BxgUOGOB5HbfNkh6LUtHX09aTzA/view

Dr. Toole

http://www.harman.com/sites/default/files/white-paper/12/11/2015 - 06:25/files/LoudspeakersandRoomsPt3.pdf

Todd Welti

https://www.harman.com/sites/default/files/white-paper/12/11/2015 - 06:12/files/multsubs.pdf



My hope is that there are enough forum members here that have more than (2) subs in their room and can offer me some first hand advice. My goal is to smooth out the bass more and gain some dynamic headroom. There is no question going duals will do that. But, the better question is how much better would it be if I were to go with (3) or even (4) of the SB12-NSD"s?

I do know that dual 15" sealed subs worked very well in my room. But, I now ask myself how would (4) of them had done. Ed Mullen emailed me back and said that (4) of the SB12-NSD's would smooth things out better and do well musically. Which, of course, is what I am after. As always, any and all help will be most helpful. Right now, I am a bit stuck on what to do and what direction to go in. Thanks!


Cheers,

Phil
 
Last edited:
lovinthehd

lovinthehd

Audioholic Jedi
In your apartment setup of unknown dimensions, unknown spl levels, let alone other details.....how could any one else know? At a guess dual subs is plenty in your apartment setting to smooth response for your seat (you got a new girlfriend you care so much about FR at her seat and she cares so much about it at the same time that it matters?).
 
speakerman39

speakerman39

Audioholic Overlord
In your apartment setup of unknown dimensions, unknown spl levels, let alone other details.....how could any one else know? At a guess dual subs is plenty in your apartment setting to smooth response for your seat (you got a new girlfriend you care so much about FR at her seat and she cares so much about it at the same time that it matters?).
Chris I did mention the cubic feet. But more specifically, my room is ~ 15.1979' X 11.9583' X 7.92'. My MLP is ~ 7-7.5' from my front-stage. High SPL is NOT my concern. But, I will admit having an extra bit of headroom is nice. My focus is more on musicality, but I do watch a movie every once in a while. I am not a gamer. Extreme low end extension is NOT needed or even wanted. I do not listen at reference levels, but do like to rock out when I can. What other details are needed for my question? I will be more than happy to answer them. My GF lives in the Philippines. There is no WAF here, but rather a DAF albeit "Dude Acceptance Factor" and I am that "Dude".........LOL!!!!!!:p:p:D:p:p

Cheers,

Phil

Please note that on the 15' wall there is a cut out where all of the pipes for my apartment complex runs through. So, my room is closer to the 1,350 Ft. ^3. My ceiling is also flat.
 
Last edited:
lovinthehd

lovinthehd

Audioholic Jedi
LOL yanking yer chain a bit Phil. Somehow I didn't see your cuft measure, tho :) Shape of the room counts, too, though as well as positioning of the subs and measured response so really hard to know. I'd think dual subs in a room that size for your own seating would be sufficient....unless you just want to get crazy but spl/headroom wouldn't likely enter into it....
 
speakerman39

speakerman39

Audioholic Overlord
LOL yanking yer chain a bit Phil. Somehow I didn't see your cuft measure, tho :) Shape of the room counts, too, though as well as positioning of the subs and measured response so really hard to know. I'd think dual subs in a room that size for your own seating would be sufficient....unless you just want to get crazy but spl/headroom wouldn't likely enter into it....
Right right. Well, I am hoping to place both subs up front in between my mains like I had the dual 15" subs before. Then, perhaps the the other (2) more near-filed. One behind my love-seat and the other in the corner behind my love-seat. The one directly behind my love-seat will be mid-wall.

My room is for all practical purposes a rectangle. But, as I mentioned earlier there is a cutout for the pipes and the rear wall has a door that opens to my BR and Bathroom. As such, it is NOT a perfect rectangle my any means. I am willing to go (4) of the SVS SB12-NSD's if it is worthwhile. Otherwise, why waist money right?

Dr. Geddes recommends (3) subs whereas Dr.Toole recommends no more than (4) in a small room. This is why I am so stuck. The SB12-NSD's at $399 are not going to be around forever. Time is a ticking away.....LOL!!!!!

Cheers,

Phil
 
MR.MAGOO

MR.MAGOO

Audioholic Field Marshall
Gene DellaSalla has some videos here or on YouTube re: subs, I'm surprised you can't search and find them. I've been here barely a year and did. :p
 
TheWarrior

TheWarrior

Audioholic Ninja
If you've been reading Harman papers then you should know that high resolution measurements (REW = 1/24 octave, although 1/16 is probably sufficient) across the listening positions as well as defining a grid across the room with measurements, as well as performing the axial mode calculations will guide you to find the best possible woofer positions.

Remember, below 200 hz, the room is in control. No super sub is going to change that, so you have to deal with it. 'Tight' and 'fast' are descriptions of the time domain, and often the failure of a sub being located in a position where multiple height/width/length mode resonances stack up.

Many people have been jumping on the miniDSP bandwagon, for the wrong reasons. Incomplete measurements lead to applying filters below the resonance frequency of the woofer, and blind boosting of low frequencies which result in the degradation of bass quality. Sure you'll hear more boom, but it will not sound accurate. With the correct measurements, miniDSP allows you to counter resonances when placement options are exhausted. You match the measured peak in frequency, amplitude, and bandwidth (Q, in this instance) and create a filter with to lower the amplitude of a resonance, or, boost a null.

And thats the short version.... it's a lot of work, but it's the only way to do it right!
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
Hi Phil, I'd only add that the number of subs is less important than proper placement and integration (said already?) Putting them where others worked may or may not work, and as Chris said in that sized room, 2 would be great. I use 3 to great effect but will have 4 mostly since I have a LOT of airspace. One thing is for sure, the price is right.


Sent from my iPhone using Tapatalk
 
speakerman39

speakerman39

Audioholic Overlord
Gene DellaSalla has some videos here or on YouTube re: subs, I'm surprised you can't search and find them. I've been here barely a year and did. :p
Yeah, I have been watching some of Gene and Hugo's videos. Which, of course, is also very helpful. But lately, been focusing more on the White Papers. Never knew there were so many different approaches as to how best to smooth out the bass response in a small room. Have found it to be rather enlightening to say the least. :):):):)

Cheers,

Phil
 
speakerman39

speakerman39

Audioholic Overlord
If you've been reading Harman papers then you should know that high resolution measurements (REW = 1/24 octave, although 1/16 is probably sufficient) across the listening positions as well as defining a grid across the room with measurements, as well as performing the axial mode calculations will guide you to find the best possible woofer positions.

Remember, below 200 hz, the room is in control. No super sub is going to change that, so you have to deal with it. 'Tight' and 'fast' are descriptions of the time domain, and often the failure of a sub being located in a position where multiple height/width/length mode resonances stack up.

Many people have been jumping on the miniDSP bandwagon, for the wrong reasons. Incomplete measurements lead to applying filters below the resonance frequency of the woofer, and blind boosting of low frequencies which result in the degradation of bass quality. Sure you'll hear more boom, but it will not sound accurate. With the correct measurements, miniDSP allows you to counter resonances when placement options are exhausted. You match the measured peak in frequency, amplitude, and bandwidth (Q, in this instance) and create a filter with to lower the amplitude of a resonance, or, boost a null.

And thats the short version.... it's a lot of work, but it's the only way to do it right!
Very nice write-up! Thanks for the info! But, I am still trying to determine which approach would work best for my needs in my room. I have already calculated the axial modes for my room. But, how do I apply that info to my room? That is another place that I am stuck.

Right now not too worried about the miniDSP as that will come later. SVS recommends the miniDSP HD. That will be the last piece to the puzzle. I know that going from a single sub to duals helps smooth out the frequency response a lot. But, how much more so going with (3) or even (4) subs do that. Is it even audible?

Cheers,

Phil
 
speakerman39

speakerman39

Audioholic Overlord
Hi Phil, I'd only add that the number of subs is less important than proper placement and integration (said already?) Putting them where others worked may or may not work, and as Chris said in that sized room, 2 would be great. I use 3 to great effect but will have 4 mostly since I have a LOT of airspace. One thing is for sure, the price is right.


Sent from my iPhone using Tapatalk
Yes, I am aware that duals helps a lot. But, adding a 3rd or even a 4th sub is what I am sizing up. I also agree the price is right if I were ever going to make such a move. Just no need to waste any money if there would really not be much of a difference. Not an easy decision here. As with anything in life, there are trade-offs! Thanks for the info!

Cheers,

Phil
 
S

shadyJ

Speaker of the House
Staff member
Very nice write-up! Thanks for the info! But, I am still trying to determine which approach would work best for my needs in my room. I have already calculated the axial modes for my room. But, how do I apply that info to my room? That is another place that I am stuck.

Right now not too worried about the miniDSP as that will come later. SVS recommends the miniDSP HD. That will be the last piece to the puzzle. I know that going from a single sub to duals helps smooth out the frequency response a lot. But, how much more so going with (3) or even (4) subs do that. Is it even audible?

Cheers,

Phil
I wouldn't try to determine room modes before measuring anything. You need to let measurements determine how many subs you should get. As for the research papers, they are all taking slightly different approaches to saying mostly the same thing, and I think the authors would all agree that measurements should guide your decisions. Three subs would probably be enough, and four certainly doesn't hurt.
 
speakerman39

speakerman39

Audioholic Overlord
I wouldn't try to determine room modes before measuring anything. You need to let measurements determine how many subs you should get. As for the research papers, they are all taking slightly different approaches to saying mostly the same thing, and I think the authors would all agree that measurements should guide your decisions. Three subs would probably be enough, and four certainly doesn't hurt.
Thanks Shady. So, do you think that it would be a good move to go w/(4) given that they are at such a good price? I am sure it wouldn't hurt. The idea is mainly to smooth things out and reduce standing waves. Of course, adding some extra headroom is also good. But, I am much more about smoothness and NOT SPL. What would you do get a 3rd or pony up and get a 3rd and a 4th? Just curious as to what you would do. Thanks!

Cheers,

Phil
 
S

shadyJ

Speaker of the House
Staff member
Four doesn't hurt. The SB12s are not output monsters, so the extra headroom does not hurt. I would be far more interested in getting a good set of measurements with respect to listening positions than I would a fourth sub. Three should do the trick, to be honest.
 
speakerman39

speakerman39

Audioholic Overlord
Four doesn't hurt. The SB12s are not output monsters, so the extra headroom does not hurt. I would be far more interested in getting a good set of measurements with respect to listening positions than I would a fourth sub. Three should do the trick, to be honest.
Thanks Shady. It is done! I have (2) more on the way as we speak. Will get around to taking some measurements this time around. Plan to experiment more w/placement as well. Not even worried right now about a miniDSP. That will come later if needed. Got an even better deal on this set than I did on the first. Just could not pass it up!

Cheers,

Phil
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
Apologize if I missed it earlier. Do you have rew and a mic


Sent from my iPhone using Tapatalk
 
speakerman39

speakerman39

Audioholic Overlord
Apologize if I missed it earlier. Do you have rew and a mic


Sent from my iPhone using Tapatalk
REW is downloaded already. Will order a CSL UMiK 1 mic tomorrow. Going to hold off on the miniDSP for the time being. SVS recommends the miniDSP HD. However, I am more concerned with taking measurements right now. I have several places that I can places my subs. Plan to experiment around to see just how good I can get it all to sound.

Cheers,

Phil
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
Nice Phil. Looking forward to your results. Fwiw, I think you made the right choice.


Sent from my iPhone using Tapatalk
 
speakerman39

speakerman39

Audioholic Overlord
Nice Phil. Looking forward to your results. Fwiw, I think you made the right choice.


Sent from my iPhone using Tapatalk
Thanks man! I just came across this deal that was too good to be true. Spent a bit more than I wanted, but I think that it will be worth it in the long run. Now the fun really begins. Got lots to move around. But, what fun fun fun right? :p:p:p:p

Cheers,

Phil
 
Irvrobinson

Irvrobinson

Audioholic Spartan
Three should do the trick, to be honest.
I agree.

I use the equivalent of three subs in my system (because I run the mains full-range, and they can produce impressive output at 20Hz), and I've been able to attain some rather impressive bass smoothness at my listening seat (measured and auditioned with test tones). Of course you know this, but others may not, running the mains full-range means you're willing to use multi-range parametric equalization on the subs, otherwise you'll get exaggerated bass, though it might be somewhat less ragged.
 
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