set up of Dual Subs... stereo or mono

[deltadube]

i don't know cause ive never had 2 subs set up but i thought the word was good to have left and right low end separation?

but i got this article

says mono is better?


can anyone give some input...

thanks

www.nousaine.com/pdfs/Stereo%20Bass.pdf

[Gary Cook]

They appear to have arrived at the same conclusion I did for myself 25+ years ago, below 80 hz sound is non directional. So given equal SPL a mono sub is indistinguishable from stereo subs. Furthermore I agree with their suggestion that even with stereo subs they should be feed with a mono signal. Personal experience also confirms that a single larger sub is superior to 2 smaller subs due to its generally longer linear travel. My ears, my room and my sources of course.


Cheers
Gary

[novisnick]

Well, from my short experience, in two channel I have a pair of subs running L/R out of my XSP-1 but I believe they are outputting mono.
Now for my HT I'm running bypass XSP-1 duel mono front and AVR duel mono rear.

My room has no perceivable nulls that I can detect and the bass is all around and not localized.
I can't remember that far back what true stereo subs sound like .

The article referred to by deltadube was mixing mid wall and corner subs. The article seemed a little muddy to me

Edit for a question:
       Is anyone else running subs like me?
       AVR has stereo subs out, I send one to my XSP-1 and go two sub out,
                                                     I send the other sub out to a splitter and on to two more powered subs

[Deleted]

I use dual subs. I have a Dual Core 2.0 that gives you the choice of either eqing: a) the two subs together as mono, or b) eqing the two subs separately in stereo. Up to 150hz I can tell no difference. Since most subs are usually crossed over below that point in my experience mono vs stereo doesn't matter.

[deltadube]

Jun 17, 2014 22:57:18 GMT -5 @islandman2020 said:

I use dual subs. I have a Dual Core 2.0 that gives you the choice of either eqing: a) the two subs together as mono, or b) eqing the two subs separately in stereo. Up to 150hz I can tell no difference. Since most subs are usually crossed over below that point in my experience mono vs stereo doesn't matter.

I guess I might as well go mono if I ever buy some subs

cheers

[Deleted]

When you do get some subs here is what I would consider based on my experience. A friend of mine bought two JBL SUB10's for 129.00 each off Ebay.
These are JBL's economy subs. We compared those two running together against one of my Polk Micropro 4000's, and one Velo. The JBL's are 150w each. The Micropro is 1200w. The Velo is 1000w. The JBL's together sounded better even though the Micropro is a 1700.00 sub, and the Velo is a 1200.00 sub. The way that dual subs help to cancel out room modes is really important. I learned from this experiment that two subs of lesser quality is better than one sub that is of higher quality.

[novisnick]

Jun 17, 2014 23:26:59 GMT -5 @islandman2020 said:

When you do get some subs here is what I would consider based on my experience. A friend of mine bought two JBL SUB10's for 129.00 each off Ebay.
These are JBL's economy subs. We compared those two running together against one of my Polk Micropro 4000's, and one Velo. The JBL's are 150w each. The Micropro is 1200w. The Velo is 1000w. The JBL's together sounded better even though the Micropro is a 1700.00 sub, and the Velo is a 1200.00 sub. The way that dual subs help to cancel out room modes is really important. I learned from this experiment that two subs of lesser quality is better than one sub that is of higher quality.

Thank you so much for stating what I have found to be a perfect match in my room. I do firmly believe your statement is 
100% fact. There are no nulls when multiple subs are used.

I just love the way my 4 smaller type subs work together, the bass is dispersed in such a way that you could never know where the bass comes from,,,only that it's there and not missing.

Nick

Edit: two subs for two channel and four subs for HT.

 

[Gary Cook]

Jun 17, 2014 23:26:59 GMT -5 @islandman2020 said:

When you do get some subs here is what I would consider based on my experience. A friend of mine bought two JBL SUB10's for 129.00 each off Ebay.
These are JBL's economy subs. We compared those two running together against one of my Polk Micropro 4000's, and one Velo. The JBL's are 150w each. The Micropro is 1200w. The Velo is 1000w. The JBL's together sounded better even though the Micropro is a 1700.00 sub, and the Velo is a 1200.00 sub. The way that dual subs help to cancel out room modes is really important. I learned from this experiment that two subs of lesser quality is better than one sub that is of higher quality.

I hope this doesn't come across as too harsh, as it's not my intention for it to do so.

A JBL SUB10 has a 10" driver (27 hz).
A Polk Micropro 4000 has a 12" driver(-3db at 21 hz).
You didn't mention what model the Velo was.

So I'm not surprised that 2 x 10" subs (with their 67% larger cone area) perform as well as (or perhaps even better than) a single 12" regardless of their amps wattage, with stereo or mono reproduction. Simplistically, one badly placed sub that doesn't sound "as good" as two well placed subs doesn't prove that 2 subs (or 3 or 4) are always better than 1. Simply that in that environment, with those particular subs, 2 sounded better than 1. Place the 1 correctly and it may well have been a different result. And/or do a respective total cone size comparison. A fairer comparison would be to included a large single driver (15" 16" 17" 18") which would facilitate the big cone excursion required for solid reproduction of frequencies below 20 hz (ie; real subwoofer territory). I think the result in that case might have been somewhat different.


I've been through the full gambit of mono, stereo and even quadraphonic (yes, I am that old) subs. But I have always returned to the single, large driver sub woofer that works in my room for my ears.


Cheers
Gary

[deltadube]

in theory in most rooms not all duals help boost the nulls and flatten the response across the spectrum.. and also increase the spl levels upto 6 dbs

adding a 3rd and then a 4th sub also do so in smaller amounts smoothing the response curve and adding spl 3 db and 2 dbs more..

that why tonight im dreaming of dual sub 2 from paradigm

duals is the biggest bang for the buck .. now what 2 subs to get ..

guess it comes down to money...

cheers

[Deleted]

Jun 18, 2014 0:55:06 GMT -5 Gary Cook said:

Jun 17, 2014 23:26:59 GMT -5 @islandman2020 said:

When you do get some subs here is what I would consider based on my experience. A friend of mine bought two JBL SUB10's for 129.00 each off Ebay.
These are JBL's economy subs. We compared those two running together against one of my Polk Micropro 4000's, and one Velo. The JBL's are 150w each. The Micropro is 1200w. The Velo is 1000w. The JBL's together sounded better even though the Micropro is a 1700.00 sub, and the Velo is a 1200.00 sub. The way that dual subs help to cancel out room modes is really important. I learned from this experiment that two subs of lesser quality is better than one sub that is of higher quality.

I hope this doesn't come across as too harsh, as it's not my intention for it to do so.

A JBL SUB10 has a 10" driver (27 hz).
A Polk Micropro 4000 has a 12" driver(-3db at 21 hz).
You didn't mention what model the Velo was.

So I'm not surprised that 2 x 10" subs (with their 67% larger cone area) perform as well as (or perhaps even better than) a single 12" regardless of their amps wattage, with stereo or mono reproduction. Simplistically, one badly placed sub that doesn't sound "as good" as two well placed subs doesn't prove that 2 subs (or 3 or 4) are always better than 1. Simply that in that environment, with those particular subs, 2 sounded better than 1. Place the 1 correctly and it may well have been a different result. And/or do a respective total cone size comparison. A fairer comparison would be to included a large single driver (15" 16" 17" 18") which would facilitate the big cone excursion required for solid reproduction of frequencies below 20 hz (ie; real subwoofer territory). I think the result in that case might have been somewhat different.


I've been through the full gambit of mono, stereo and even quadraphonic (yes, I am that old) subs. But I have always returned to the single, large driver sub woofer that works in my room for my ears.


Cheers
Gary

The Velo is in my signature. It is a Velodyne SPL-1000R. If I was ever able to get better bass over a pair of "lesser" subs by using one higher quality sub the benefit was improved even further by then using two of the higher quality sub. I failed to mention that in the experiment that the SUB10's do not have room EQ built in. The Micropro and Velo do. The EQ in the Velo is the superior one of the two IMO. We ran both the auto EQ systems in the Micropro, and the Velo. I felt that by running the auto-eq systems that it was now being unfair to the SUB10's, but I was determined to prove that using one of my "high quality" subs would be superior against the dual SUB10's. We spent about two hours setting up the Micropro, and then the Velo in various positions in the room. Again, I was determined to find that sweet spot that would prove me right, and had we more time we might have concluded differently. When we got tired of experimenting though we both concluded that even with running the room EQ of my two subs we preferred the response we were getting with SUB10's.

Not originally so, but I am now of the opinion that it's not just about sub quality that gets the better/smoother bass, but also about bass frequencies emanating from two different positions in a room simultaneously. My experience has been that this definitely helps to tame standing waves/room modes in a way that I have never been able to achieve with just one sub.

I think that Dr. Floyd E. Toole's writings in Harman Kardon's White Paper on Using Multiple Subs is very informative and dead on.

[Deleted]

Also, I would like to mention that had I owned the Dual Core at the time, and used it on the SUB10's, I believe the smoother response of the dual SUB10's would have been enhanced even more.

[Deleted]

i have said it and will say it again..

buying a second sub was THE biggest gain in improvements I have made in my existing theater bar none...

[pedrocols]

I have had two different pairs of subs. In my room, in both situations adding a second sub was beneficial. I use an Antimode to smooth the response.

[deltadube]

well looks like the price of a sub just doubled eh!! he he he

[Priapulus]

The mythical xmc-1 back photo shows l-sub and r-sub output. I presume that means stereo output. I hope it is programmable stereo or mono x2. It would seem that the designers of the XMC-1 sees stereo subs as useful; what do the other highend processors provide? I prefer two mono subs.
Sincerely
/b

[Gary Cook]

Jun 18, 2014 19:04:18 GMT -5 Priapulus said:

The mythical xmc-1 back photo shows l-sub and r-sub output. I presume that means stereo output. I hope it is programmable stereo or mono x2. It would seem that the designers of the XMC-1 sees stereo subs as useful; what do the other highend processors provide? I prefer two mono subs.
Sincerely

I presumed that the XMC-1 dual sub output would be available in stereo for those that use the sub output more as a woofer than sub woofer. Hence have frequencies over 80 hz which can be directional. For those that use the sub output as a true subwoofer then mono would be available.


Cheers
Gary

[gv3]

In one of my home theatre setups I have 4 Martin Logan Motion 12s, a Motion 8 center and 2 ML Dynamo 300 subs. I experimented with placing the subs next to (outboard of) the front Motion 12s, and also with them oriented with one in front and one behind our listening/viewning position. Subjectively I favored them both in front outboard, and this seemed to be confirmed by measurements with my Dayton Audio OminMic V2. Hope this helps.