Hooking up 2nd sub for 2 ch.+home theater

weiser · December 2002

I have a PSW350 connected to LFE on receiver(100 hz) and plan on adding a second sub ( M&K v2 ) to the receiver main L/R pre-outs. ( crossover controlled by M&K sub )
I feel this way when listening to music only in 2ch. I have the benefit of the M&K with the mains.
Also, when in DDor DTS etc. I have the Polk 350 dedicated to the LFE and the M&K solidifying the front stage.

Any thoughts?

I have also heard alot on this forum about where to set the speakers ( Large or Small ) for surround setup. For most the best setup is to set all speakers small and the sub on thru LFE from receiver, however, the ideal setup for home theater is to set all speakers to large with subs running off LFE,pre-outs on receiver from all speakers. ( would require multiple subs)

Adding additional subs in order of importance ( my opinion) would be;

1st LFE
2nd Mains ( off receiver pre-outs L/R)
3rd Front Center
4th Surrounds
5th Rear Center

Of course you could run a sub off each individual channel throughout your system but this is getting crazy!

I am just wondering if others have experimented with the above and what they have found?

gidrah · December 2002

I'm not familiar with Kinima speakers (link?), nor do I have dual subs, but will try to offer an opinion anyways.

I have 1 sub w/ the receiver's X-over set to 100hz. Whether I listen to 2-ch or DD/DTS, my sub hits when it needs to. This is with the fronts @ large.

I like the dual sub theory. Especially the - 1 thru LFE & 1 thru pre-outs. Try each one in each place and decide from there.

I personally don't think there is a benefit to setting the mains to small when they are capable of being set to large, especially if you hook you sub to pre-outs. While the sound is omnidirectional, the sense of realism of vibrations coming from one side or the other is not.

weiser · January 2003

The Kinima speakers are made in Canada and are visually and sonically outstanding! I have owned them for approx. 9 months, and all I can say is wow!
http://www.zetagcorp.com/
I find that any speaker I set to small loses some punch ( as I suppose it should without lower freq. running thru). When set to large the sound just seems to envelope more which you seem to agree with also!
I have tried so many configurations with speaker settings and have to conclude that large for all works best with my system.
The LFE Polk sub crosses at 100 Hz from Marantz receiver and the M&K crosses on the sub at 70Hz.
Polk suggests the main center CS400i be set to large which automatically sets my mains to large on Marantz Receiver.
Does anyone run this center on small? And?

I quess I will continue buying more subs until my wife leaves me!
Isn't this a great hobby!

Dr. Spec · January 2003

Well, this topic has been discussed extensively over at HTF by very experienced enthusiasts and DIY sub builders who have already gone down this road, and also by manufacturer's representatives and company owners like Mark Seaton, Brian Bunge, Tom V., Stryke Audio, etc.

While there are exceptions to every rule, here is the general consensus amongst the top audio guys over there: Multiple sources of low bass emanating from different locations in a single room create all sorts of funny room modes, standing waves, peaks and nulls, and totally conspire against obtaining a flat bass FR at key listening positions.

This isn't just vaporware pie-in-the-sky theory - these guys actually tried this stuff - with upwards of 7 subs in the same room, with sophisticated state-of-the-art equipment to measure SPL and FR throughout the entire room. They even used feedback destroyers in an attempt to flatten FR in the room.

The result was invariably the same - one sub in one corner always gaves the flattest FR at the key listening positions, with the least standing waves and nulls. Each time a sub was added in a different location, it became progressively harder and harder to keep a flat FR, and with four subs it was a downright mess.

There is ONE guy over at HTF who has managed to successfully pull off multiple subs in his HT room - his system costs (I'm not joking here) $93,000.

For the rest of us mere mortals, the pros strongly suggest ONE low bass source in the room. Not enough SPL for you? Add a second sub right next to (or stacked upon) the first, or buy one bigger/better sub.

Doc

weiser · January 2003

Thanks for the info Dr.Spec!

So in my particular case the best way to position the subs is either one on top of the other or within close proximity?
Also, having one sub run off the LFE of the receiver and the other sub off the pre-outs(Mains) of the receiver?
Set the LFE sub with the SPL meter thru receivers pink noise and the other sub with trial and error off 2 channel mains listening?
Having them stacked and hooked up this way in no way will affect the sound adversely?
I will connect in this way if this is the consensus out there!
This actually would make things alot easier because of the fact that I have already located the ideal sub placement in my home theater room.

Thanks for the help!

Let me know if this makes sense!

weiser · January 2003

In addition to the above I will set my speakers as follows;

Mains

Large
Center

Small
Surrounds

Small
Subwoofer

Yes

When running in processor mode( dd, dts etc.) I have the Polk sub running off LFE receiver and the M&K sub running off Mains.
When in 2 channel mode ( S-direct mode on Marantz) The LFE is disabled and I have the M&K sub to carry the lower freq. for stereo listening.

Does this sound feasible!

Dr. Spec · January 2003

For DD/DTS playback, I recommend:

Both subs off the LFE channel using a Y-splitter, and all speaks set to small, regardless of their real or perceived low bass capability.

Why is the LFE disabled for 2 channel mode? If true, this presents a problem.........

weiser · January 2003

One caveat: Because SOURCE DIRECT bypasses bass management, the left/right pair of loudspeakers are driven full range. To keep your subwoofer active youll have to run interconnects from the left or right preamp outputs and manually adjust your subwoofers level and crossovera small price to pay for the added resolution. While the pure stereo sonics of the Marantz may not be the last word on an absolute level, this fine two-channel performer isnt more than a few syllables short.

This is a quote from a review done on the Marantz SR6200 from spring 2002. The sound is awesome in SOURCE DIRECT because it bypasses all tone controls, bass mangt, etc. for a pure line signal in 2 channel but to keep sub active.......

So this is my dilemma!

Hence the reason for sub off pre-amp outs and large selected for mains in surround processing menu.

wlrandall · January 2003

Jokes on me-again!

To quote Doc:
"For the rest of us mere mortals, the pros strongly suggest ONE low bass source in the room. Not enough SPL for you? Add a second sub right next to (or stacked upon) the first, or buy one bigger/better sub."

I've been pulling my hair out for months with the obvious staring me blindly in the face:

1) Living room is rectangular, ~19' x 21'
2) Everything is placed symmetrically, from the TV being in the exact center to the front mains being the exact same distance from one another and including my 350s that WERE 1' off the side walls and 2' off the back in the corners.

Hmm...standing waves and nulls, my room was full of them and it was driving me nuts. Too much bass here, hardly none there, so on and so on.

The obvious is exactly that. With everything being equidistant, I set myself up for an acoustic nightmare with the subs. It created a huge dead spot right in the middle of the sweet spot for viewing. Not good. Add to that the harmonics and there were more sour spots.

They are now stacked in one corner and the results are phenomonal, can't wait to recalibrate.

The down side? It even sounds better outside. Now my neighbors are going to hate me even more.

Thanks for the insight Doc!!

Wally

weiser · January 2003

Stacked in the corner it shall be!

You have them stacked in a corner not equidistant from the 2 walls( for best results). Now for the siily question. Does it matter which way the drivers are pointing ? ( forward like mains or at right angle or backwards) I know bass is omnidirectional and I am probably answering my own question but I thought I would ask.

Also, any idea as far as my last post concerning hook up options;
1 sub to LFE on rec.
1 sub to pre-outs rec.

I can split off the LFE of receiver to both subs but when I listen to music only in Source-Direct ( Marantz SR6200) I lose the use of subs. Any ideas?

Any input would be helpful!

gidrah · January 2003

Forget any manufacturer claims. Dr. Spec is THE bass authority.

Dr. Spec · January 2003

Originally posted by wlrandall
They are now stacked in one corner and the results are phenomonal, can't wait to recalibrate.

Good for you, Wally! Kick some butt on your neighbors!

Ed

wlrandall · January 2003

Feel sorry for them sometimes-they're such a nice young couple...naaaahhhhhh! I think I'll depth charge them tonight with U-571.

Wally

goingganzo · January 2003

i would point the subs foward tward the peeps. the olny thing i hate where i have my sub is that i can tell where the bass is comeing from. it is on the left side of the room in the center of the wall.

weiser · January 2003

Any comments on my previous post!

Dr. Spec · January 2003

Did we steal this thread? Sorry. Anyway, I was at a loss for further advice when you stated your SR6200 cuts the subs in source direct. Anyone else?

weiser · January 2003

Technically the LFE still works but no bass management therefore, I assume, you need to have a crossover( the subs) in order to have the sub active in 2 channel( the reason for hook up to rec. pre-out mains). The crossover in receiver must be bypassed also so I don't know how else to do this. The assumption is that for 2 channel listening most will have large mains not requiring a sub and want a line level source that is discreet.( nothing in the path for better sound)
I sure would like to hear from others who have a Marantz receiver to see what they are doing!

What is the effect of hooking up the LFE from rec. to sub and hooking the pre-outs from rec. to sub.. With 3 connections to sub I am not sure if this is the best setup or not!( assuming 1 subwoofer in system)

I have heard of others who connect this way and just wondering if anyone has any experience with this hook-up method!

Dr. Spec · January 2003

I think you can safely hook up LFE unfiltered, and line level filtered L/R if you want, as long as you don't send it multiple signals at the same time, which I don't think will happen with your Marantz. Give it a try and see what happens.

TonyPTX · January 2003

Originally posted by goingganzo
i would point the subs foward tward the peeps. the olny thing i hate where i have my sub is that i can tell where the bass is comeing from. it is on the left side of the room in the center of the wall.

If you're not limited to location (for asthetics or to please the wife/significant other) try moving the sub to the front half of the room and offset it's distance from any sort of symetric distance. I've got my sub on the right hand side about 1/3 of the way from the front wall and it's pretty hard to pick out where the sub is.

weiser · January 2003

Here is a link that I have read that I think most will find interesting. It discusses bass management issues ( like what I had in previous posts) and suggestions for speaker size configurations in surround setup. The 3 page article is one of the reasons why I believe the mains should always be set to LARGE if they are full range bass capable or running second sub off pre-outs. Any comments?

http://www.audioholics.com/techtips/setup/loudspeakers/bass_management_TRS1.php

Dr. Spec · January 2003

From Audioholics:

"That being said, I believe it is best for the Main speakers (assuming large bass capable ones), or the subwoofer (if optioned) to produce the bass from the rear and center channels. In addition, I really feel that in a large room, such as your living room, the ultimate combination for critical two-channel audio is large bass capable speakers with a musical subwoofer. Large speakers tend to blend better with a subwoofer, assuming proper phasing, which results in a seemliness transition of bass between the speakers and subwoofer."

"Large Speaker: Bass capable speaker able to produce full bass frequencies down to about 20 Hz."

First, who has mains flat to 20 Hz? Hell, most subwoofers are only flat to 35 Hz. Even if your mains are good to 30-35 Hz, how loud can they play for HT without distorting, and how much current drain are you going to place on your receiver while doing so? Also, many DVDs contain a full range signal in the mains channel - 95% of the mains out there cannot do this justice - not even close.

Also, read the last few posts in this thread:

http://www.hometheaterforum.com/htforum/showthread.php?s=&threadid=117169&pagenumber=2

BTW, Poindexter has that $93,000 system - check that out! He DOES run full range all around, but few can pull it off successfully.

In particular, I liked this last post from Mike Price:

"I would like to point out that, yes, Mike (Poindexter) has a really amazing setup that is far from typical. The important thing here is that it is VERY DIFFICULT to set up your system so that bass is produced from multiple sources (especially more than two) and avoid cancellation problems. The room interactions can really get out of hand with, say, five speakers running full range... especially in a smaller room. From what I know, such a setup would usually require phase correction and EQ... and/or a careful, computer-optimized placement."

"Basically for most of us, even those with tower speakers, setting everything to small and having a single (or multiples in one place) subwoofer reproduce most of the bass. I know it's that way for me - I can't even get a pair of mostly full range speakers to reproduce bass properly."

Weiser - of course, run your system however it feels and sounds best to you. We can always agree to disagree. One thing I know for sure - my RT800i's which are rated to around 35 Hz would spit a lung if I ran them on large at high volume for HT.

For 2 channel, they do much better on large. Even then I don't run them that way. One listen to the Gladiator soundtrack through the RT800i's on large vs. the RT800i's on small and the SVS in the loop will settle that argument very quickly. That is a very bass demanding CD requiring power, articulation, and most of all, really deep extension. There are notes on this CD that my full range Advents and my RT800i's completely ignore.

Doc

weiser · January 2003

You're right! We'll have to agree to disagree!

Although I believe most of your points are quite valid. The subwoofer placement in one primary location is definitely correct for alot of reasons. The running of mains large is more a personal preference for MY system as the majority of systems out there are not capable of deep extension in the mains. You have to realize also that even though my mains are flat to about 40Hz I also have the M&K subwoofer running off the pre-out mains of receiver to extend to lower freqs.. That combined with the Polk sub off LFE of receiver( taking bass from center,rear small selection) more than compensates for the bass from all dvd's out there including Gladiator (excellent movie). I have measured readings of 105-110db split out of the meter in the listening position without any signs of stress whatsoever ( other than my ears). For the majority of viewing or listening most people will not listen at these extreme levels. So I guess,in conclusion, the debate will continue!

Hooking up 2nd sub for 2 ch.+home theater

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