Stereo subs, is this worth it ?

[Tagglez]

I have read and heard it mentioned that some people set up stereo subs (as opposed to dual mono subs) in order to achieve 'stereo bass', whatever that is, when playing music.

My question is, is this something actually worth doing, as from what I understand, several points would seem to make this a worthless exercise.

Firstly bass frequencies are non directional with respect to human hearing, so bass fundamentals that would be played through a sub can't really be localised by us to a left or right channels so to speak. Higher harmonics of those bass fundamentals, however, can be localised but they would most likely be above the subs xover, so would be played left/right in the main speakers anyway.

More importantly though, most recorded music has the bass mixed as mono. That's the way most sound engineers seem to do it, so in that respect, there is no 'stereo bass' to reproduce from most musical recordings. Therefore 'stereo subs' will do nothing for that, bar the rare niche audiophile recording that hasn't been mixed that way. Most music lovers collections though are not primarily made up of niche two microphone recorded obscure jazz pieces...

So, stereo subs, real gains or merely aesthetics ?

 

[lovinthehd]

You'd also lose the ability to use sub pre-outs/bass management with almost all gear, thus adding to difficulty in setup let alone available content....personally it's not even tempting to setup stereo subs altho I have read of some who are proponents and have such setups (for movies as well).

 

[elf1]

While I don't feel I am qualified to answer your question, I do know there is a lot of criteria that should be considered when choosing a sub. I am presently testing two L12 subs from Rythmik. They offer a 45 day trial period and free shipping, however you pay for freight back if you don't like them ($40). SVS will pay freight both ways.
I suggest you contact either of them and they can guide you. Since it is no risk trial you can order two if budget allows and try one sub and than two. If one sub works for you - send the other sub back.
Good luck!
Elf1

 

[Tagglez]

You'd also lose the ability to use sub pre-outs/bass management with almost all gear, thus adding to difficulty in setup let alone available content....personally it's not even tempting to setup stereo subs altho I have read of some who are proponents and have such setups (for movies as well).

The one advantage I have in my system is that it's all PC based content being fed to my receiver. With that setup I'm using EQ APO for Windows to do all my bass management etc (with that all being disabled in the receiver) So technically I can bass manage stereo outputs, in fact individually bass manage every channel, as well as copying channels across to others via hp and lp filters etc if I wanted using EQ APO.

But yes, that aside, I can't really think of any content that has genuine stereo bass in it, (the odd piece of music might have bass panned left to right for effect but the majority of music and film content seems to have it all mixed as mono)

 

[William Lemmerhirt]

Imo you’re original hunch is correct. Tom nousaine did some in depth experiments with stereo subs in the 90’s and iirc found absolutely NO benefit whatsoever, due to the reasons you brought up. Unfortunately someone bought the domain names or something where he published his tests and I cannot find them anymore. Multiple subs are absolutely beneficial, but not set up in a “stereo”.

 

[Tagglez]

Interesting, I will do some searching on Tom Nousaine to see what I can find. My aim is to have multiple subs when I can afford it (currently running just the one)

 

[William Lemmerhirt]

Interesting, I will do some searching on Tom Nousaine to see what I can find. My aim is to have multiple subs when I can afford it (currently running just the one)

Welcome to the rabbit hole! I use 3 in my system and I think lovinthehd has like 9! Not really(wink). 4 I think he’s using. Seen guys use more than that too. Crazy...

Tom was kind of a crazy genius who just never stopped asking questions. A great contributor. S&V might still have some of his work in their system. Not sure though.

 

[everettT]

That APO will help eq, but does nothing for crossover, slopes, etc. stereo subs are used in close proximity to the LR speakers and tend to run higher crossover to the mains. Setup is not as easy as using room placement for best low bass.

 

[Tagglez]

That APO will help eq, but does nothing for crossover, slopes, etc. stereo subs are used in close proximity to the LR speakers and tend to run higher crossover to the mains. Setup is not as easy as using room placement for best low bass.

Not quite sure what you mean when you say EQ APO will do nothing for crossover, slopes etc ? I ask because I do indeed have EQ APO set up and running perfectly with crossover filters in place. (In my case 4th order Biquads for the relevant channels set up in EQ APO's config file)

 

[lovinthehd]

@Tagglez how do you connect your pc to avr/amps/subs?

 

[lovinthehd]

Welcome to the rabbit hole! I use 3 in my system and I think lovinthehd has like 9! Not really(wink). 4 I think he’s using. Seen guys use more than that too. Crazy...

Tom was kind of a crazy genius who just never stopped asking questions. A great contributor. S&V might still have some of his work in their system. Not sure though.

LOL only 4 in the main setup, but a total of nine in the house (and three yet to be built)

If you want to see a crazy setup including awesome amounts of sub bass for L/R/C check out BassThatHz' system over on avsforum.com....here's his theater setup thread

 

[Tagglez]

@Tagglez how do you connect your pc to avr/amps/subs?

HDMI out from the GPU (graphics card), to HDMI in using the 'pure direct' mode on my receiver. Thereafter speakers etc connected as normal (but all set to large to disable the receivers bass management, so I can control that from the Windows app)

 

[everettT]

Not quite sure what you mean when you say EQ APO will do nothing for crossover, slopes etc ? I ask because I do indeed have EQ APO set up and running perfectly with crossover filters in place. (In my case 4th order Biquads for the relevant channels set up in EQ APO's config file)

Explain your detailed setup please. How did you determine what filters, eq, peq etc. were needed. I’ve run stereo subs with electrostatic panels and with full range single driver setups using different processing units, both required a “second” set of eyes to help. If your running passive crossovers in your mains, it’s a little more challenging to perfect. I’ve tried to use ARC via computer and found it inconsistent.

 

[lovinthehd]

HDMI out from the GPU (graphics card), to HDMI in using the 'pure direct' mode on my receiver. Thereafter speakers etc connected as normal (but all set to large to disable the receivers bass management, so I can control that from the Windows app)

So how would you implement stereo bass with that connection setup?

 

[William Lemmerhirt]

LOL only 4 in the main setup, but a total of nine in the house (and three yet to be built)

If you want to see a crazy setup including awesome amounts of sub bass for L/R/C check out BassThatHz' system over on avsforum.com....here's his theater setup thread

Lol! I had to rib ya a little.
Btw, the link goes to ummmm, something else, but his setup is awesome. A bunch of others too.

 

[Tagglez]

So how would you implement stereo bass with that connection setup?

Hmmm, let's see. Firstly you would need 'spare channels'. (unused surround channels for example, so lets say 'rear right' RR and 'rear left' RL) So, if your content was never more than 5.1 say, you would set up EQ APO to be 7.1 (and the receiver likewise) If your max is 7.1 then you would set it up as 9.1 (key is, you need spare channels) Then, in Windows, in EQ APO you would use the apps 'copy' function to copy the full main left channel to the spare left surround channel and apply the low pass filter to that channel. Likewise with the main right channel.

If you are also using the system for movies as well as music you would also copy in the LFE channel to each of those spare channels.In EQ APO 'SUB' is the LFE content. So, in EQ APO it would look something like this :

For the right channel

Copy: RR = R+SUB (So, the rear right channel becomes the sum of the right plus LFE)
Filter ON LP (with the required settings based on your chosen xover frequency)

and for the left

Copy: RL= L+SUB
Filter ON etc

You can add in other channels too, if you want to be sure of capturing low frequency content in them, for example adding in the center channel.

Copy: RL= L+C+SUB

With that done, you then take the 'rear right' preamp output from the receiver and connect that to the right sub. And the 'rear left' preamp output to the left subwoofer.

And that gives you the 'stereo bass'. [You could also use the subs own xover filters rather than setting the filter in EQ APO]

 

[Tagglez]

Explain your detailed setup please. How did you determine what filters, eq, peq etc. were needed. I’ve run stereo subs with electrostatic panels and with full range single driver setups using different processing units, both required a “second” set of eyes to help. If your running passive crossovers in your mains, it’s a little more challenging to perfect. I’ve tried to use ARC via computer and found it inconsistent.

I will add some detail tomorrow, as here in the UK it's rather late !

 

[lovinthehd]

Lol! I had to rib ya a little.
Btw, the link goes to ummmm, something else, but his setup is awesome. A bunch of others too.

Just tested the link, it took me to the thread for his theater build....what did you get? PM me if you would....