Are two less powerful subs better than one more powerful sub?

[jcisbig]

Hey All,

This has probably been asked before, if so, feel free to point me to other threads. But basically, my question is this:

Could 2 smaller/less powerful subs be comparable in performance or output to 1 larger/more powerful sub.

Assuming this setup is 50/50 music/movies, what do you guys think?

Two subs will deliver more headroom (depending on placement), more frequency smoothing (depending on placement), depending on driver size it could be moving more air, etc.

To bring this to a practical level, what would be your guesses regarding running two SVS pb-1000 subs against a PB-12 plus?

What about 2 Rythmik FV12s against a Rythmik FV15HP?

You get the idea. I understand that in some cases you'll be losing some or a lot of low end extension, but what about the rest of the experience?

Thanks!

 

[j_garcia]

Depends on the subs obviously, and the room is a factor as well. I've tried multiple subs at once, but never two identical ones so far. The results were still good, but I am not displeased with one good sub. If the difference in performance is large between the smaller and larger subs, then one might still be a better choice. In the examples, I'd expect 2 PB1000s to easily exceed a single PB12. For the Rythmiks, it might be closer. The other thing is, you are effectively increasing output only, you will not change the capability of those subs. The location of the two within the room along with careful calibration can result in better response in the room than a single one however.

 

[Steve81]

Here's the AH article on this topic: Are Two Subwoofers Better than One? — Reviews and News from Audioholics

To bring this to a practical level, what would be your guesses regarding running two SVS pb-1000 subs against a PB-12 plus?

In this particular case, a single PB12+ would still have an output advantage (it's roughly as powerful as two PB12-NSDs stacked). OTOH, if you've got a lot of big peaks and dips at the listening position, you can't really solve that by just getting a more powerful sub.

 

[j_garcia]

Sorry, missed that he said Plus. I think a Plus would likely win in output.

 

[lsiberian]

Ideal is 4 subs. One in each corner, but rarely do wives approve that. I do plan to add subs down the line and having a solid sub to build off of is nice.

 

[jcisbig]

Thanks for the replies everyone. Something that I experience, and I'm not sure if others do, but when I place my sub (hsu vtf-15h) next to one of my Aperion Verus Grand Towers at the front of my room, certain songs cause the low end to be biased to the left or right, depending on where I have my sub. Because of this, most of the time I have my sub directly behind my listening position so that it is not left/right biased in any way. The problem with this of course, is that sometimes I can feel/hear/tell that the low frequencies are coming from behind me instead of from the front of the room where the rest of the music is coming from.

I know that some of the above issues can be solved by lowering the overall volume of the sub so that it blends better with the rest of the sound, but I've already taken the sub much lower than I would like. I have what appears to be, at least to my ears, a very balanced sound at the current volume that my subwoofer is at.

Bottom line, I like how the sub up front sounds, but the left and right bias when it is up front I don't like so much. Therefore it goes in the back.

All this has lead me to think that adding another sub up front would be best, so that there is no more left/right bias. However, the purpose of this thread is to educate myself on what I should recommend to friends as they piece together their systems.

The new SVS pb-1000 option is very intriguing to me because, if the specs are right, you have a sub that can deliver 20hz sound. Having two of these subs would increase headroom for 2/3 ish the cost of the pb-12 plus. In this scenario, you'd have two capable subs that will increase headroom, and you can have symmetrical placement next to your front LR speakers so that the bass isn't biased to the right or left.

Thoughts?

 

[j_garcia]

If it is a room mode causing the issue, two subs could still potentially have the same issue, but it sounds like it might help in your case. Are you doing any EQ? Do you sit close to that opposite wall or farther from it?

 

[jcisbig]

I'm not sure if it's a room mode issue or not. I'm about 14 feet from the front wall, and about 8 from the back wall. My room is roughly 21ft long and 14ft wide with an 8ft ceiling.

 

[j_garcia]

Sounds like how I had mine before. My previous room was 13.5'x24', but I had a high angled ceiling too. I had serious room modes at my 80Hz x-over where I was sitting. I moved 1ft closer and it helped. If you aren't going to run some curves on the room, I'd maybe try sitting in a chair in front of and behind your couch and see if the sub responds noticeably differently; if it does, it is probably a room mode.

 

[jcisbig]

Forgot to mention that I'm running Audyssey MultEQ as well. The sub does not sound drastically different in front of or behind the listening position. There are some differences, but not like, "woah, it's much more ____ here."

Back to my original question though. If an SVS pb-12 ultra were a perfect 10 in terms of output, dynamics, sound quality, headroom, etc. What would two pb-1000 subs rate out of 10 for those same categories?

 

[walke108]

Thanks for the replies everyone. Something that I experience, and I'm not sure if others do, but when I place my sub (hsu vtf-15h) next to one of my Aperion Verus Grand Towers at the front of my room, certain songs cause the low end to be biased to the left or right, depending on where I have my sub. Because of this, most of the time I have my sub directly behind my listening position so that it is not left/right biased in any way. The problem with this of course, is that sometimes I can feel/hear/tell that the low frequencies are coming from behind me instead of from the front of the room where the rest of the music is coming from.

I know that some of the above issues can be solved by lowering the overall volume of the sub so that it blends better with the rest of the sound, but I've already taken the sub much lower than I would like. I have what appears to be, at least to my ears, a very balanced sound at the current volume that my subwoofer is at.

Bottom line, I like how the sub up front sounds, but the left and right bias when it is up front I don't like so much. Therefore it goes in the back.


Thoughts?

Have you tried lowering your crossover to say 60 to solve your sub localization issue?

 

[jcisbig]

Yes, I have tried lowering the crossover frequency. The issue is, I think I like more bass than the average person and when I lower it to 60hz I lose some of the tactile feel that I like from my 15" woofer in that range.

 

[j_garcia]

I would pose this exact question to SVS (or whichever sub's you are pondering) and see what they say.

 

[shadyJ]

I would just get another VTF15h and set them next to each of your front left/right mains, that should solve the problem of localization, it will likely smooth out the room response, and it will give you a boost in headroom. I wouldn't want to replace the VTF15h with two substantially weaker subs. The SVS 1000 subs and NSDs won't be able to contribute very much if used with a VTF15h, and to replace a VTF15h with a pair of either would be a heart breaking downgrade in dynamic range. If I were to replace a VTF15h with two lesser subs, I would want those subs to be up to the task of matching the dynamics of a VTF15h. I would go for a pair of Hsu VTF3s or Power Sound Audio XV15s.

 

[jcisbig]

ShadyJ,

Yes, that would be the best option for me. However, the wife says no.

The purpose of this thread isn't primarily for my benefit, I think I derailed it myself with a few comments of my own. Basically, I'm trying to figure out what recommendation would work best for my friend, who has yet to buy a sub or subs for his system. He's on a budget, so he can't buy two of the best subs. I'm just curious if he would be really satisfied with something like a pair of the svs pb-1000 subs versus one of their more expensive models.

 

[shadyJ]

Ok, I see. In that case I would say I think most people would be more satisfied with one more powerful sub in most situations. However, if your friend doesn't intend to listen to anything loudly, two less powerful subs might give you a more even and less localizable sound and so be preferable, but that will come at the expense of output. If your friend is more after that massive wall of sound feeling that you get at those THX promos at the Imax, one powerful sub is going to get you closer to that. If your friend can swing a Rythmik FV15HP, that would be the beast to get. If your friend can swing a bit more cash, check out the JTR Captivator 1000, that will give you a sensation likely far beyond what any single Rythmik, SVS, or Hsu sub can give you. For dual subs at just over 1k, I would suggest a couple Hsu VTF2 subs, there is a small discount on them at the moment, and two will give you lots of output and pretty tight bass as well.

 

[ack_bak]

If your going with two less powerful subs vs one powerful sub, I would not give too much up in extension... Try to find two lesser subs that still offer good extension and then adding an additional matching inexpensive sub (or four) will makeup in the output department by giving you another 3-6db+ deepening on your room and location and you will get the benefit of smoother bass response throughout the room.

I tried mixing and matching two lesser subs and it was futile.. Ended up going with one larger more expensive sub and it really improved my bass. Now I am going with four identical DIY subs which should get me flat to 8hz or so with authority.

 

[jcisbig]

ack_bak,

This is why I've been primarily asking about the svs pb-1000 in this thread. SVS states that it will dig down to 19hz or so. I haven't seen a professional review of the sub yet, so whether or not it can actually do this is something that I think is still untested. But if it did, having two subs that can perform that well might be a good way to get the benefits of dual subs while still maintaining good performance. Perhaps at the cost of a little output.

 

[ack_bak]

ack_bak,

This is why I've been primarily asking about the svs pb-1000 in this thread. SVS states that it will dig down to 19hz or so. I haven't seen a professional review of the sub yet, so whether or not it can actually do this is something that I think is still untested. But if it did, having two subs that can perform that well might be a good way to get the benefits of dual subs while still maintaining good performance. Perhaps at the cost of a little output.

SVS's ground plane measurements are pretty spot on with what Ricci and others measure, so if they claim it will dig down to 19hz or so, I believe it. I think two of the PB-1000's would make a very nice combo for $1K shipped. More then likely this will be enough output for you and if you can try near field placement, give that a whirl. With dual subs, I think it is even more important to measure your room and the effect placement has with the dual subs. If you are able to measure and move the subs around, I think you will be able to achieve what you are looking for.

 

[shadyJ]

ack_bak,

This is why I've been primarily asking about the svs pb-1000 in this thread. SVS states that it will dig down to 19hz or so. I haven't seen a professional review of the sub yet, so whether or not it can actually do this is something that I think is still untested. But if it did, having two subs that can perform that well might be a good way to get the benefits of dual subs while still maintaining good performance. Perhaps at the cost of a little output.

Compared to what a $1k sub can do, that will come at the cost of a lot of output, not just a little. I think a Hsu VTF15h or PSA XV15 would dwarf the output of two PB1000s. It would not be a close contest at all. I think the PB1000 could do 19 hz, but it won't do it very spectacularly, and if you look at SVS's own FR chart for it, it looks to be down by 6 dB at 19 hz from a flat FR. When you factor in human's lower sensitivity to low frequencies, if you are going to chase after 20 hz output, you will want it at a level that's easily perceivable, and not something that you will have to strain to hear. I would say if you are going for two subs, I would go for two Hsu VTF2s instead, they will have substantially more output and deeper extension, but they are slightly more expensive and are a bit larger and heavier. Even then, I don't think two will quite match the output of a single VTF15h, but they will come a lot closer.