Q: "Full Range" w/ stereo subs

Posted by: R. Mackey

Q: "Full Range" w/ stereo subs - 06/17/05 11:45 AM

Hi gang,

Trying to do some long-range planning for my system. At this point the weaknesses are "speakers" and "room." I'm thinking of going to a three-sub configuration, with L and R subs handling the low frequencies sent to each main speaker, and the third sub working in traditional fashion, taking care of the LFE channel and bass sent to the surrounds only.

I've seen some real bass fiends here. Has anyone tried this? Worth doing?

I run about 98% music including multichannel. Lots of it being loud symphonies, organ, deep electronica, and electric-bass heavy rock.

{Current setup}
Pioneer DV-45
Outlaw 950 / 7100
Behringer DCX2496
Mains: KEF Q-30 (bi-amped)
Surrounds: KEF Q1s, Q9c
Sub: Hsu VTF-3

Thanks, all.
Posted by: sluggo

Re: Q: "Full Range" w/ stereo subs - 06/17/05 01:35 PM

If you're comfortable with lots of tweaking, that's good, because that's what's in store for you. LF characteristics can cause multiple subs to cancel each other out and reduce the bass levels instead of increase them, based upon placement and room shape [you mention that room is a weakness, so this may be a problem]. On top of that, LF being non-directional sonically, you'd benefit more from spending the money on a single, powerful sub than multiple lower-power subs [and who doesn't want a giant sub? laugh ].

If your VTF-3 isn't cutting it in your room, have a look at this one , it's kind of big but I'm told it's a gutshaker. Other Outlaws in the forum also mention some good experiences with subs, you may want to search for some posts.
Posted by: gonk

Re: Q: "Full Range" w/ stereo subs - 06/17/05 03:20 PM

There are a few folks around here that are sincere proponents of stereo subs, so what you are doing has been done in one form or another by several people. There's a thread or two somewhere around here with some good tutorials on stereo subs that might be of interest. If you have trouble getting three subs settled into your space, you could also consider stereo subs that share LFE duty. It may be a bit odd to do in light of the 950's triple crossover (and may introduce some concerns with channel delays, although I'm not sure), but you could think about setting all of your channels to "large" in the 950 and putting an ICBM between the 950 and the 7100. That would let the sub's LFE output and the crossed-over data from center and surrounds be split between two subs, each of which would be assigned the task of handling low frequency duties for their respective main speaker. It's a thought, and there are some other good ideas floating around the forum. As sluggo says, if you don't mind tweaking your system, the reports I've read indicate that it can yield some very positive results.
Posted by: R. Mackey

Re: Q: "Full Range" w/ stereo subs - 06/17/05 11:43 PM

I should have dug a little deeper... found this old thread by SoundHound (where is he, anyway?) with lots of good information.

I should explain what I think it might achieve. My VTF-3 has plenty of power and extension, but I find it more localizable than it should be. I also wonder if compressing bass signals from all six channels onto a single signal is costing me some detail, though it's just speculation.

My sub XO is set to 80 Hz (I'm using the 950's analogue for SACD/DVD-A -- it's a real help), and on some material the pull towards the sub is obvious. 60 Hz or lower would be better, but I can't do that on hi-res without an ICBM.

I visited Dr. Hsu once, and after he found out that I play organ, he fired up his twin TN cylinders on some nice, deep music... heavenly. laugh

You both make good points about placement. I'm thinking of a symmetric setup, with L and R subs right next to the main speakers, and the LFE sub beside the listening position. At that point, the L and R should always add constructively because of identical pathlength (zero for the LFE, which will have a constant phase shift). I'll still have room modes to deal with, though.

Yeah... could be a lot of tweaking. Sounds like fun to me.