Stereo Sub Vs Dual Mono

[My adventures in stereo]

I am presently running a triple SVS PB 2000 sub system, calibrated through REW/ dirac, through minidsp SHD
Which sounds fantastic
I have run dual mono subs in the past & prefer the 3 sub setup, for the wider sweet spot & the head room available

Never tried a stereo sub system, where one is dedicated for the left channel & one for the right channel
The idea being to emulate vintage large woofer speaker systems, like the KEF 105 ( never heard it)

The obvious negatives :
- The loss of gain from the subs not working together
- Most music is not mixed for stereo sub usage

Worth a try ?
Welcome input on the above, thanks

 

[ex audiophile]

Try this video, helped me understand the pros/cons. My experience trying it both ways using Anthem STR preamp (ARC Genesis) and switching back and forth I've always preferred dual mono.

audioholics mono vs stereo subs - Bing video

www.bing.com

 

[My adventures in stereo]

Thanks for the link, very informative
Makes a compelling argument for leaving thebass system in mono

 

[goat76]

The obvious negatives :
- The loss of gain from the subs not working together
- Most music is not mixed for stereo sub usage

Worth a try ?
Welcome input on the above, thanks

I have my 2 subwoofers set up in stereo right beside/outside of each main speaker, and right from the start I thought it sounded way more spacious than my previous setup with just one subwoofer. It sounds so good I have no urge to even try them in mono.



As I see it...

In practical use, there is no real loss of gain having the subwoofers playing in stereo, because as you say, most recordings are mixed (or summed) with the sub-bass content right in the middle of the mix anyway. So for the most part, the two subwoofers will receive the same or almost the same signal anyway so they will basically share the workload in a similar way as if they were set up in mono. So I don't think you need to be worried about any real loss of gain.

But in cases when you play some content that really contains some stereo bass information, it will probably not that often be anything brutal like a kick drum or any other main bass-heavy instruments being hard-panned in the mix. More likely the hard-panned bassy sounds will be subtle occasional things that can bring some envelopment to the overall sound.

That is my experience anyway and seems to be what David Griesinger talks about in his papers (which I read long after my own findings).

http://www.davidgriesinger.com/asa05.pdf

 

[My adventures in stereo]

I have my 2 subwoofers set up in stereo right beside/outside of each main speaker, and right from the start I thought it sounded way more spacious than my previous setup with just one subwoofer. It sounds so good I have no urge to even try them in mono.

Thanks for the in put & for sharing your first hand experience
Also the David Reisinger link

I have my front subs close to the main speakers too
The adjustments to convert to Stereo sub can be done easily for testing out stereo subs, will give it a try

 

[ZolaIII]

It only makes sense if you properly crossover (Linkwitz–Riley filter) the sub's above 80 Hz (100 Hz for example) in order to get a heat of the main speaker woofers and lower their THD at for them high SPL levels. All home speakers with 7~8" woofers will benefit from this. Other thing to recommend in such case is closing the port's of main speakers to more even their main - uper bass response, cut enclosure resonance caused by port and improve (mostly with all described already) their midrange response.

 

[Sokel]

Stereo subs is absolutely needed in classical in set ups that mains don't go low by their own.
Unlike other popular music there's a whole bunch of hard-panned instruments that go low in each channel,same goes for chorus recorded this way.
Put them in mono and image becomes strange.

 

[AdamG247]

Stereo subs is absolutely needed in classical in set ups that mains don't go low by their own.
Unlike other popular music there's a whole bunch of hard-panned instruments that go low in each channel,same goes for chorus recorded this way.
Put them in mono and image becomes strange.

I agree with this. When in 2ch stereo listening there is no LFE signal. So the AVR strips low frequency (as determined by your Main L&R speaker crossover settings) and you get stereo imaged bass. To me it makes a huge difference in soundstage width and depth. JMHO

Post editing this statement: While the AVR may be stripping the left and right low frequency content and routing this to the Subs. It is not technically Stereo Bass and is probably a summed variation of dual mono bass. The exact process is unknown to me and I was incorrectly assuming the end result is Stereo bass. It is not. Apologies if I misled anyone. My thinking was flawed and I jumped to an incorrect conclusion. Thank you for your understanding.

 

[anotherhobby]

I agree with this. When in 2ch stereo listening there is no LFE signal. So the AVR strips low frequency (as determined by your Main L&R speaker crossover settings) and you get stereo imaged bass. To me it makes a huge difference in soundstage width and depth. JMHO

Same here. I prefer stereo subs for 2 channel content, at least when you also physically locate the subs appropriately right and left. I currently have four 8" subs in my office, with two in front as right and left under the mains, and the other two in back as right and left, as seen in my office layout down below. Before going to 4 subs, I was running two subs in stereo. At that time, I tried dual mono subs and found much preferred stereo subs.

I figured that might change with 4 subs, so I started out trying to do mono again. It took a lot of fuss with REW/MSO/Dirac, but I eventually got a good quad mono setup that measured objectively well and sounded subjectively good. However, after listening to the mono sub setup for over a month, I reconfigured the four subs for stereo, and now I'm much happier with it. For me, stereo subs provide a better sense of channel separation and more spaciousness than mono subs, at least in my configuration. There is also far more deep stereo bass than people think, especially outside of pop/country music.

 

[phoenixdogfan]

I actually configure my system 2 ways. When I run stereo, I set it up as 2.2 with Dirac DLBC doing stereo with two separate crossovers. It's sent via USB to my OCTO DAC 8 and Channel 1 & 3 are for Left main and sub (LS 50 Meta & Sb2000), and 2 & 4 are for Right Main and sub. Subs are within 24 inches of mains and are crossed over at 150 hz via DLBC.

When I run home theater on the same system I set DLBC up to run 5.1 (again with a 150 hz crossover for LFE). Channel 1 is Left, channel 2 is Right, Channel 3 Center (instead of left sub), Channel 4 is LFE, Channel 5 is Right Surround, and Channel 6 is Left Suround. I use a Little Bear Switch on channels 3 & 4 output by the Octo: With one setting it sends distinct Left and Right stereo sub information to the L-R subs, with the other setting it sends center channel information out of channel 3 and channel 4 sends mono LFE information to the two L-R subs via a Y split connection. Thus I have a two channel set up with stereo subs, and a 5.1 channel set up with the mono LFE information sent to the two different subs.

The stereo is for when I play music and the 5.1 is for movies and other multichannel material, the two configuration layouts are configured as different zones in JRiver.

 

[jhaider]

I briefly played with using stereo subs in our 2-channel system (augmented by two subs crossed much lower). It was a waste of time. The bass was not as smooth or effortless as using all the subs in mono, and the spatial variance was far worse in the room. Perhaps more time EQ'ing it could have equalled a simple mono system, but it was apparent to me that the effort would not be remotely worth it compared to pressing a button and letting DLBC do its thing, and reclaiming that tweaking time to enjoy music.

Maybe with next gen room correction systems it will be a debate worth having again.

 

[Chrispy]

I agree with this. When in 2ch stereo listening there is no LFE signal. So the AVR strips low frequency (as determined by your Main L&R speaker crossover settings) and you get stereo imaged bass. To me it makes a huge difference in soundstage width and depth. JMHO

What avr offers stereo subs?

 

[jsilvela]

I'm very curious about placement, if you're using stereo subs.
I recently got my second sub and am using a Welti-inspired configuration with symmetric front-back placement to help reduce modes.
Doesn't seem stereo sub would be any good with this placement.
Does stereo sub necessitate front-left front-right placement? Or at least left-right?

 

[FrankW]

- Most music is not mixed for stereo sub usage

True for pop, rock etc, completely untrue for classical, jazz, acoustic, etc.
Regarding non mono subs, our resident audio perception luminary J_J has not only spoken on this, he has demo'd it for decades.
If you want to hear a non mono bass system today, go here

 

[AdamG247]

What avr offers stereo subs?

Running the Denon 8500h. Manual link

Word choices matter and I now clearly realize that saying “Stereo Subs” is probably technically incorrect. My apologies did not intend to mislead. After further reading I suspect they are not true Stereo Subs. Thanks for pointing that out to me

 

[My adventures in stereo]

I'm very curious about placement, if you're using stereo subs.
I recently got my second sub and am using a Welti-inspired configuration with symmetric front-back placement to help reduce modes.
Doesn't seem stereo sub would be any good with this placement.
Does stereo sub necessitate front-left front-right placement? Or at least left-right?

From my understanding of the subject, I would go with placing the subs in a front left/ right config, close to the main speakers

 

[NTK]

I'm very curious about placement, if you're using stereo subs.
I recently got my second sub and am using a Welti-inspired configuration with symmetric front-back placement to help reduce modes.
Doesn't seem stereo sub would be any good with this placement.
Does stereo sub necessitate front-left front-right placement? Or at least left-right?

These are Dr. Griesinger's conclusions.

http://www.davidgriesinger.com/asa05.pdf

 

[Chrispy]

Running the Denon 8500h. Manual link

Word choices matter and I now clearly realize that saying “Stereo Subs” is probably technically incorrect. My apologies did not intend to mislead. After further reading I suspect they are not true Stereo Subs. Thanks for pointing that out to me

No, Denon doesn't offer stereo subs, altho your model can separately set level/delay for two subs. I can't think of any avr that offers that, altho I wonder if some of the top end processors might these days.

 

[chych7]

If you have a subwoofer with high-level inputs, you can connect them with your L/R speakers to get a stereo signal to the subs. I guess you can use a high-level extractor if your subs only have low-level/LFE inputs. I tried this with my subs (using high level inputs) and didn't hear an improvement, but I mostly listen to music that probably doesn't have a stereo bass signal.

I was also thinking that bass should be omni-directional and this shouldn't matter, but I just proved myself wrong on this. Played some test tones on my L/R speakers, and I can easily localize them being left or right all the way down to 40 Hz, and starts becoming omnidirectional around 30 Hz (where the speakers roll-off). So if the audio content has a stereo signal for bass, I can see there being a benefit if you can set it up right. However, if this means you have bass peaks/nulls, then it may negate any improvement to soundstage.

Perhaps another solution if you are using an AVR, have speakers that can play fairly low, and have an external DSP for the subs: turn on the double bass/LFE+main setting. Use the DSP to blend in the subwoofers correctly with the speakers, fix any room modes, and fill in the low-bass freqs (miniDSP/Multi Sub Optimizer might be able to achieve this). This way the speakers can play a fair bit of the stereo bass signal, and you still get the benefit of properly positioned subwoofers to fix room modes.

 

[sarumbear]

Running the Denon 8500h. Manual link

Word choices matter and I now clearly realize that saying “Stereo Subs” is probably technically incorrect. My apologies did not intend to mislead. After further reading I suspect they are not true Stereo Subs. Thanks for pointing that out to me

I’m still none the wiser. How are you sending left and right signal’s sub frequencies separately to the left and right subwoofers?