Stereo subs or one big sub??

pacifico · « **on:** 18 Apr 2006, 01:50 pm »

I am trying to decide on the following. As my family grows and my house shrinks, I need to give up some space from my stereo. I am considering switching from my paradigm monitors/stands to Gallo ADivas. Only problem is: What to do about Bass? Will one massive sub be good or would I be better off with two lesser powered ones. Getting the two lesser powered ones would not cost much more. The "big poppa" would be 250W while the stereo subs would be 100W a piece. They are kinda small so size would be a problem for me in this case. Ilisten to music almost exclusively. I am really intrigued with the concept of stereo subs.

jermmd · « **Reply #1 on:** 18 Apr 2006, 03:25 pm »

I don't think there's any need for stereo subs. What frequency do you plan on crossing the Gallos over at? The higher the frequency, the more directional the sound. This is pretty much a non issue below 80hz. A single good sub is easier to place and set up and should give you plenty of decibals.

pacifico · « **Reply #2 on:** 18 Apr 2006, 03:32 pm »

As these are smallish speakers (4-5 inch driver) I guess I would cross them pretty high. But its any one's guess. The room I would use them in is medium sized.

klh · « **Reply #3 on:** 18 Apr 2006, 03:48 pm »

If you're going for good sound qaility, I'd get a pair. I'd first try running them mono with one centered at the front of the room and the other centered at the back and 180 out of phase (as per the harmon white paper). It's supposed to even out the frequency response while still re-enforcing lower frequencies. If you haven't read it, do a google search... it really is compelling. If you try it but aren't impressed, you could run them stereo, but then you'll have cancellation issues and placement could be problematic.

pacifico · « **Reply #4 on:** 18 Apr 2006, 07:23 pm »

Thanks all for your advice and observations. Running the subs at opposite poles of the room is interesting, doesthis require equal lengths of speaker cable? I have still not ruled out running one good sub. I need to do some listening in my house and at the dealer.

A few more details: I think the pair would be front firing if I bought them and the single sub would be down firing. I am interested in choosing between two smaller gallos TS1(?)s (100W each) or one ACI Force or the Titan if I can afford it.

Russell Dawkins · « **Reply #5 on:** 18 Apr 2006, 08:15 pm »

you should also factor in that more sound sources means less room mode excitation. A single sub will excite room modes maximally, whereas if two subs are used, assuming that different modes are excited by each sub, the strength of those modes will be half. Room modes are particularly obvious in the bass range, which is why when you walk around a room the bass sounds so different in different areas.

nathanm · « **Reply #6 on:** 18 Apr 2006, 09:03 pm »

Has anyone ever has set up their system with the best-compromise scenario reached by that research; i.e. four subs placed north east and west with you in the middle? Like most things in audio, the execution seems expensive and impractical, but I'd like to hear it.

I would go for two lesser powered subs in stereo myself. It seems more 'purist' not summing anything to mono.

I'd also stick the subs right next to the main speakers. Seems to make sense. I've found that putting subs in weird locations doesn't quite work out. (the front and back positions) I mean, if you've got the kick drum split into two halves with the transient coming from the mains and the thump coming from the rear it just doesn't feel right. Might work better in a real big room with dimensions in excess of 20-30 feet, but then everything does!

jermmd · « **Reply #7 on:** 18 Apr 2006, 10:40 pm »

The whole mono vs. stereo concept is moot if you can't localize the source. I'm not sure about room mode issues but a single sub is so much more convenient that I think it's the way to go.

miklorsmith · « **Reply #8 on:** 18 Apr 2006, 10:51 pm »

I don't think bass is completely nondirectional. Of course, as the bass frequencies get higher, location is more obvious.

I've heard the room mode issue is significant, but I've also heard integrating stereo subs can be tricky.

With little speakers, I'd get stereo subs and get them as close to the mains as possible. Two little speakers and one big sub sounds like a nightmare to integrate.

Rob Babcock · « **Reply #9 on:** 19 Apr 2006, 02:38 am »

I'd vote for two big subs.

John Casler · « **Reply #10 on:** 19 Apr 2006, 03:35 am »

Quote from: Rob Babcock

I'd vote for two big subs.

Well if it is a "vote" I'd have to go with 4 BIG (as in LARGER) subs

nathanm · « **Reply #11 on:** 19 Apr 2006, 04:27 am »

Why stop there? Why not stack them four high against every wall?

Can you still have bass modes if the walls ARE subwoofers?

Russell Dawkins · « **Reply #12 on:** 19 Apr 2006, 05:35 am »

Only four high?
Heck, I heard of a crazed enthusiast back in the 60's who basically covered the entire wall of the speaker end of his room with woofers. I'll bet it didn't sound bad, either.

On the subject of bass, I've heard that once you hear the sound of a really large mouth bass horn, there is no going back.
Like this: http://www.diy-systems.com/
click on showroom, go down 6 and the one on the far right - Peter's. Click on the image.

pacifico · « **Reply #13 on:** 19 Apr 2006, 11:21 am »

Thanks guys...Now we are as far from the problem as we can get...Hell why don't we try measuring bass response in a hyperbaric chamber to see if changes in atmospheric pressure will do anything :lol:

O.K. No really, I appreciate everyone's help. After reading many of your responses, I had a thought. Wouldn't a pair of stereo subs placed close to the speakers be nearly the equivalent of a two way system with powered woofers? Essentially, I would just be getting rid of the speaker cabinets...Right?

MaxCast · « **Reply #14 on:** 19 Apr 2006, 01:34 pm »

Right. But your speaker placement may create a low frequency mode at the listening position and you would be unable to move the woof.

csero · « **Reply #15 on:** 19 Apr 2006, 01:53 pm »

Quote from: nathanm

Why stop there? Why not stack them four high against every wall? Can you still have bass modes if the walls ARE subwoofers?

Yes, you can create modes if you feed them with the same signal, but more importantly it will not help with spatiality. You need big and long lateral difference in the bass at the listening position to have spatial feeling.
If you delay/echo the signals according to a real or simulated acoustic space, the modes will not be noticeable. This is more like Wave Field Synthesys and Ambisonics than high-end.
Also stereo sub is very important, and you need wide separation for the proper spatiality in the bass. If you go for stereo sub, put them wide to the left and right of you instead of close to the stereo speakers.

BTW I have tots of 12" plus 2*18" fed with the proper signal.

budyog · « **Reply #16 on:** 19 Apr 2006, 02:45 pm »

I am going for 2 large subs!

As I continually build/upgrade my system and since going to the satellite/sub way and owning a larger sub for many years, I have always thought "how would it sound with 2 large subs"?
I also think that all low frequencies can't and don't care if they are non-directional, I don't care what paper or the spec people say.
Due to ACI changing the look of the "Maestro" I have ordered another one for delivery sometime in early summer to match the rest of my ACI speakers.
I am going to place them under my "Panorama's" with some custom 5" stands between them . I will post pictuers at some point.
I know with one sub and the way I have my system set up that I can hear where the low sound/feel is coming from. With 2 subs, I feel that the sound will even be fuller. It will fill in the whole that I hear in the wall of sound that I have now.
I can't wait! I will let you all know. Stay tuned

nathanm · « **Reply #17 on:** 19 Apr 2006, 03:31 pm »

I had my 2-channel system set up with stereo VMPS largers in the corners on end for awhile and it was darn good (well, not for getting through the doorway) but elected to split them up for the surround system. If the room were bigger I'd definitely go back to that arrangement. I only say 4 high assuming the average 8 foot/243cm high ceiling. Certainly you could go higher if your room allowed!

Getting the 2nd sub on top of the first would be tricky enough, the 3rd and 4th may require some kind of lift truck, or definitely a couple two tree strapping fellas to help! heh!

pacifico · « **Reply #18 on:** 20 Apr 2006, 04:22 pm »

OK...So I think I got it. Two satellite speakers with a wall of subs. Is that everyone's concept here? :lol: :lol: :lol: