SWARM / Multi subwoofer questions

Hello haywood310,

     I think going from one Hsu ULS-15 sub to two is a very significant improvement that begins to smooth out the perceived bass response peaks and dips in the room, increases maximum bass impact, reduces the bass production required from each sub, improves bass dynamics and even improves the soundstage imaging.  
    I believe going from two ULS-15s to three will be a further significant improvement in most, if not all, of the areas going from one to two provided.  According to Earl Geddes, going from three to four subs will only provide a marginal improvement but, in my experience, utilizing four subs was the threshold to attaining near state of the art bass performance.

     As for configuration, settings and positioning of all 3 subs, I'd like to know more about your system and room before offering suggestions. Here're some clarifying questions:

1. I understand this is for music only but do you plan on incorporating home theater in the near future?
2. What are your room dimensions: length, width and ceiling height?
3. Along which wall are your main speakers and equipment/rack-long wall or short?
4. Is the room carpeted and are there any irregularities (large openings, doors, odd sections or shapes)?
5. Are you wanting to optimize performance at a single listening position or do you want good performance over more than one seating position?
6. If you just want a single sweet spot, where exactly is this seat located within the room?

Thanks,
  Tim

A quick search turned up 537 different subwoofers. And subwoofer development must really be going gangbusters because amazingly every single one of them is the best newest most powerful and greatest because of their cone, coil, port, lack of port, huge size, small size, voice coil, EQ, active, passive, amp, wired connections, wireless connections,
sorry, running out of room to even list all the reasons why each one is better than all the others.

Man I would hate to be the schmoe who messes up and buys one of those loser subs. Although I guess any time he wants to feel good about his mistake he can always parrot ad copy. Not that anyone would ever do that.

If you’re willing to consider heresy, an Audyssey equipped pre-pro will be an excellent solution. It’s not just the room correction, either.   The crossover handoff will be optimized and IME inaudible.

But, you have to turn in your audiophile man card

One more thing without exception 
the New SVS -3000 SB subwoofer is the best under $1500 on the market 
just compare , it is a 13 inch version of their great ultra 16 sub
ithas a great app , very powerful amplifier 52 bit analog devises microprocessor 
the only split pole voice coil on the market which allows precision Bass even at low volume the others donot . I have owned Rythmic, mj acoustics JL audio
REL,Velledyne all models were more expensive  . This sub has a 45 day audition ,and free shipping , and free  return if not completely satisfied, and a 5 year parts and labor warranty .
Nobody else can touch all these features and under $1k .  Buy 2 subs with an added extra $100 off. Honest tight tunefullBass to 18 HZ it is a Great sub ,
just check it out nothing to loose and the competition will not offer a trial .

Hello this link for the free REW sub program ,
buy the dsp,usb Mike,  on this link under$100 And eq one sub at a time and fantastic results.
http://www.roomeqwizard.com

You should take a look at the Rythmik subs.  If you talk to Brian the owner you will be in for a treat.  He has a doctorate in Electrical Engineering.  He is a genius.  They sell direct and put very expensive drivers and amplifiers in their subs.  Their Direct Servo technology is patented and incredible.  Call Jim Salk at Salk Audio.  He will explain why he feels Rthmik subs are the most musical.  He builds custom subs using Rythmik drivers and their Direct Servo American amplifiers.

It’s a little more speedy ,  the legacy wavelet is a step up from a Mini dsp

Right. Only its not exactly like you will feel its still needed. More like when you add it you will be surprised and wish you'd done it sooner.

Its hard to explain but I think it has to do with the way really low bass works. With moderately low bass, like 30-40 there are lots of times where its pretty easy to spot. You hear a bass line, get the feeling that as the notes go lower they should be all the same, but they're not. They trail off. So you know to do something about that.

Really low bass though is completely different. Its not even hardly heard at all. Its more a sensation. And its there in some surprising ways and sometimes where you would never expect it. A lot of the time its not even really part of the music. Its more a part of the room. In other words a big recording room or concert hall, it has a natural reverb to it that is very low depending on its size. You don't really hear this, but you do feel it. Sense it. This is what people mean when they say good bass opens up the sound stage. Its really opening up your room by making it feel not like the little room that it is but the big one the music was in. We're used to that from good imaging where the high frequencies seem to make the stage extend out beyond the walls. But with really low bass its not just in front on the stage. You are enveloped in it.

So best move is get another ULS 15 since Im already two deep into the HSU's? and then a fourth if I feel its still needed?

The main idea behind the Swarm or distributed bass array is that while any one sub is going to produce lumpy modal bass response, a whole bunch of them in different locations will produce a whole bunch of lumpy modes that combined together result in smooth, deep, articulate bass.

It works. Tim and Duke and often times even me will go into all the many solid reasons why- the physics, scientific research, human hearing physiology, etc- which is certainly nice to know. But honestly, it works so well you will be 90% of the way there and pleased as punch even if all you do is plop em down wherever they go, twist a few levels by ear, and sit back and enjoy. Its that good. Because you have science on your side.

Briefly, its not that EQ won't help. A little EQ can always tweak things a little better. But the main reason people think they need EQ so much is because they are using just one or two subs and getting the awful response one or two subs always give. Soon as you go to four (or more!) a lot of that need goes away. What little you are left with can be easily handled with the level adjustments on each of your subs.

Again, yes you will be able to get it "more perfect". But the improvement from four subs vs three is so much that if it was me I would take whatever money I was thinking of spending on EQ and just buy another sub. Or two.

Another thing is, its really hard to ever have too much bass. Don't misunderstand me. Not saying you can't turn the bass up too high. You certainly can do that. What I mean is it is really hard to have too much low frequency headroom. Vast majority of the time, vast majority of recordings, there's hardly any really low bass. It is as if your awesome Swarm subs do not even exist. Every now and then though, you play the right thing loud enough, its freaking insane how much bass energy there can be! It was always there, you just never knew it, because even with one or two really good subs they just never got it to a level you could notice. Seriously. Get four. You will see.

So in other words if you can buy four awesome 15" subs then go for it. But just keep in mind, the improvement from four is so great you will probably be better off with four less awesome subs than two or even three really awesome subs. 

One real life example since this is a hard concept to grasp. There was a guy here with four ordinary two-way speakers. Not subs just ordinary 8" or maybe 10" two-way speakers. He asked what's a good way to hook em all up. I said two normal stereo, use the other two like subs, down on the floor facing the wall. He was blown away how much smoother, better and more articulate the bass got. So the Swarm concept is so powerful you don't hardly even need good, just more.

http://jamesromeyn.com/old-pages/home-audio-gear/dsa-1-0-distributed-subwoofer-array-5-pieces-4k-usd...
Here is a long article about how it works and set up.I have four subwoofers that I can dial in individually for my two channel set up.The DEBRA swarm system is more 'room friendly' and I would have gone that way if I didn't have two SVS subs already.I just added two more.No DSP needed.No need to spend $$$ on subs with room correction software.Millercarbon and noble100 will jump in I'm sure with more information for you.I love what it does for my system and highly recommend it.There is no downside.I don't believe you will ever read that someone tried it and took it back out because it didn't work with their system:) 

Contact Duke at audiokinesis@yahoo.com.  He knows more about multiple sub woofers implementations than most.  In fact, he markets a 4-sub system called the SWARM. 

Also forgot to mention... possible outputs into Sub Xover are RCA's and speaker level since my XLR's from my Aleph P are direct into my Aleph 5. My experience has been speaker level to the sub is always been the most transparent but Ive never seen a line level X over that isnt garbage. So guessing RCA it is and run the swarm in Mono.