[Timothy Reason]

Hi I currently have a 6.1 Home Theater using a Yamaha RX-V2300 receiver.  I am currently working on designing a dual sub workup with an external 2 channel amplifier.  My question is how do I go about doing this off my Yamaha Reciever?  On the back there is a single RCA jack for the subwoofer that runs a single line to my current single sub built in amplifier.  
Now if I go to a seperate 2 channel amp, dont I need a Left and Right side off the Yamaha Receiver if I want my subs to play in stereo?   Right beside the single jack is a left and right labeled "Main", and below that a left and right labeled "Rear Surround"  And next to thos two single RCA jacks labeled "Center and Rear Center"  
Would I use the jacks labled Main or rear surround but then also have to find some kind of crossover?  Or am I totally in the wrong place?  Can any of you dual subwoofer people out there help me out?  tyvm!

[bubba966]

All you need to do is run a high quality splitter off of your sub out to use two subs.

[Timothy Reason]

And this will create a correct Left and Right Sound stage in Stereo?  I mean if there is an intended Boom on the left side of the room, I would like to hear it that way.  Second, if all I need it a splitter, can to give me some idea what I am looking for?  Or is it simply like a Y cable in car stereo, where I can connect a Y to a left signal and one to the right signal and end up with 4 connections instead of just 2 off the same line?

[Timothy Reason]

After doing a little more research, it appears for me to achieve a stereo subwoofer setup with 2 subs from my single sub output on my Reciever I need a Outlaw ICBM Bass management piece correct?

[Rob Babcock]

Not really.  If your reciever does bass management (as virtually all modern ones do) then you have no use for the ICBM, which is just a crossover.  And it certainly isn't going to turn your mono sub output into a stereo one- nothing can do that.  As Bubba said, it's a simple matter to split the single output into two, but both will carry the same signal.

You'll get differing opinions depending upon who you ask, but very low bass really is omnidirectional.  IMO, the only way you can "hear" where the sub is at (ie "localize") is from harmonics or higher sounds coming from it.  In practical terms it doesn't matter as all subs will play some higher sounds (no matter how steep the filter, it's not a brick wall), so there can be localization, just not for the reason people mistakenly believe.

The long and the short of it:  unless you use an external x-over and separate amps for sub & the other speakers, you won't be able to get stereo sub output and use the sub out without some major gear changes.  But splitting the sub output from the receiver will get you 90% of what you're looking for, especially if your main use if HT.

[ooheadsoo]

Speaker level input on your sub amp?  Failing that, how about ACI's speaker to line level convertor?

[MaxCast]

You could take the main outs and split them.  One going to a outboard amp for the main speakers and the second going to two powered subs.  You would then have to select no subwoofer so all LFE is sent to the mains outs.  Your main speakers would run full range so your sub xo would have to go low enough to come in under them.

Why do you want two subs?

[Rob Babcock]

Okay, I was a little confused.  I thought he said he had a stereo amp running a pair of subs, but that must just be what he planned to do.  If you use a pair of passive subs and external amps, you'd need an external X-over to get stereo bass, and then of course you'd do as MaxCast suggests and let the sub to 'NO' or 'OFF' as the case may be.  With just a single sub, you're of course not going to get stereo bass.

[bubba966]

Well, if you're going to use dual subs in an HT setup, you do as explained by just splitting the sub out off the Yamaha to the amps for the subs. Use either a Y cable, or a Y adapter that's got no cable (just plugs), or have a custom cable built with two outputs off of one input. I used to run both of my subs in stereo off the one sub out on my Pioneer Elite. But that meant I was using 3 splitters (the plug only type as they're a bit better). But I wanted to get rid of those 3 splitters so as to get rid of the signal degredation that was going on with all of the splitters. So I had Bolder Cables build me a custom sub cable that took the 1 sub out off my Elite, and split it into 4 outputs to use on my 2 subs w/out using any splitters. That cut a whole lot of connections and improved the subs more than I figured it would.

Stereo subs are used mainly in 2ch only setups. And that's an entirely different setup.

As Babcock already mentioned, subs are outputting info that's not directional. So it doesn't really matter where they are as they're not directional. Stacking a pair of subs in one location works very, very well. It's also a whole hell of a lot easier to try to setup & properly adjust when they're stacked as opposed to placing 2 subs in different locations.

[F-100]

After doing a little more research, it appears for me to achieve a stereo subwoofer setup with 2 subs from my single sub output on my Reciever I need a Outlaw ICBM Bass management piece correct?

You can use either Outlaws ICBM or Paradigm X-30 for this purpose. In my HT setup, I'm feeding the signal from the receiver into  Outlaw ICBM and then to an external amp that drives two subwoofers. I get great result with this setup.

[doug s.]

for ht, i defer to others, as i don't do ht.  but, for audio, i would *definitely* run each sub w/a separate left & right channel signal, yust as yer monitors.  for whatever reason, even if ya have a steep x-over slope, & a wery low x-over point, you *will* hear improved soundstaging running true stereo subs. all one needs to do is to change the subs from stereo to mono, if your outboard x-over allows this, to hear the difference.

doug s.

[JDUBS]

I would run the subs off of the main L and R speaker outputs.  This would then use the speaker level input on the sub amps and would allow the main speakers to roll off naturally.

I use this method currently with my computer setup (JVC F10 receiver, modded Polk RTI-28's and dual Yamaha YST-SW205 subs) and it works great!

-Jim

[bubba966]

I would run the subs off of the main L and R speaker outputs.  This would then use the speaker level input on the sub amps and would allow the main speakers to roll off naturally.

Sure, that works great for 2ch applications when using powered subs.

Not quite applicable for Timothy's application though.

[Digi-G]

I've been considering doing a similar setup - dual subwoofers from my Denon receiver.  Although my reasoning was to get a smoother bass response throughtout the room, and not so much the left/right bass seperation.  I assumed that I would use a simple Y-splitter which means both subs would receive the same signal.

My receiver has a dedicated LFE output, which seems to work really, really well (esp. for HT), and I wouldn't want to change that.  But it means I have to live with mono bass/LFE (my receiver doesn't have any options for outputting stereo bass/LFE).  While there may be some L/R separation down in those nether regions of bass, for me the smoother bass response seems more important.

One more thing - I think if I had the option of changing my crossover to the sub, I would change it from 80hz to 60hz (mostly to keep the bass from 60-80hz coming from the main speakers).

[ctviggen]

Has anyone done a test with stereo subs versus two subs fed the same signal (from both front right and left speakers)?  I went to two subs to get stereo subs, but my Proceed AVP won't do stereo subs correctly.  My Proceed AVP is supposed to put all sub info from right speakers on the right sub and all sub info from the left speakers on the left sub, and split the LFE and center channel to both subs.  It does work in non-stereo modes, but in stereo, only one sub works.  

How much low frequency (<60Hz) is really on separate channels and are stereo subs better than two subs (I have my two subs sitting behind each R/L speaker)?

[JDUBS]

I would run the subs off of the main L and R speaker outputs.  This would then use the speaker level input on the sub amps and would allow the main speakers to roll off naturally.

Sure, that works great for 2ch applications when using powered subs.

Not quite applicable for Timothy's application though.

Woops...didn't read closely enough  

[doug s.]

Has anyone done a test with stereo subs versus two subs fed the same signal (from both front right and left speakers)?  I went to two subs to get stereo subs, but my Proceed AVP won't do stereo subs correctly.  My Proceed AVP is supposed to put all sub info from right speakers on the right sub and all sub info from the left speakers on the left sub, and split the LFE and center channel to both subs.  It does work in non-stereo modes, but in stereo, only one sub works.  

How much low frequency (<60Hz)  ...

my marchand x-over has a "mono sum" switch.  i would lose some soundstaging w/it depressed.  more on some recordings than others.  

i remember speaking w/psychicanimal once; how he inadvertently switched the "sum" switch on, when he was dusting his equipment.  then, when listening later, he couldn't figure out what happened to his soundstaging.  when he discovered the mono sum switch engaged, he switched it out & all was well again.

doug s.