Stereo Sub Vs Dual Mono

[sigbergaudio]

Actually, if you read the other paper I have now linked multiple times, the cardioid bass you design is actually helpful here, even if you weren't aware!
Music? Just about any classical track >1980s?

It's a bit tiring that you keep assuming what I know and don't know.

 

[FrankW]

I'm going strictly by what you post

 

[sigbergaudio]

Lateralisation, as it relates to subwoofers, is a spatial sensation, more like a "wide" vs "narrow", start reading from here

Not sure that is correct, are you sure you understand this yourself? Lateralisation so far seems to being referenced exclusively in papers where they use headphones for the testing. Do you have a reference to where an alternative definition is presented?

 

[sigbergaudio]

I'm going strictly by what you post

You are assuming by what I post.

 

[FrankW]

Not sure that is correct, are you sure you understand this yourself? Lateralisation so far seems to being referenced exclusively in papers where they use headphones for the testing. Do you have a reference to where an alternative definition is presented?

There's a saying here you can only led a horse to water...

 

[sarumbear]

There's a saying here you can only led a horse to water...

No need to be rude!

 

[theREALdotnet]

Getting the subs and the speakers close to each other kinda brought back the depth continuity that good stereo setups have. A lot of people focus on stereo imaging with regards to left right and center but front and back have so much going on as well and a good bass managed setup should preserve that imo.

This is actually one of the things I tested last night, but forgot to mention. I compared two-sub mono bass with no-sub to see whether the mono bass ruins the stereo image. This is easy for me to do since I just have to mute the DAC that runs the subs. I did not perceive any change in soundstage width or depth, or anything about the stereo image “feeling different” when toggling the two-sub mono bass on and off.

I used mainly classical and jazz material that is known for well recorded sound stage, but if anyone wants to suggest any particular test tracks I can repeat this test anytime.

 

[theREALdotnet]

I have not experienced that the ability to reproduce a spatial sensation (like the low frequency content assisting to create the illusion of a concert hall, church or similar sensory illusions of being within a large space) is reduced in dual mono configurations.

This is an experience I share.

 

[mdsimon2]

I use stereo subwoofers with LR2 60 Hz x-overs but will admit that I find for the majority of content the left and right channel being sent to each sub is identical.

IMO the biggest difference between stereo and mono subwoofers is level. If you are summing L + R to create your mono signal and the content in each channel is identical this will result in a +6 dB signal being sent to each subwoofer compared to stereo. This is definitely audible.

Michael

 

[sarumbear]

I use stereo subwoofers with LR2 60 Hz x-overs but will admit that I find for the majority of content the left and right channel being sent to each sub is identical.

IMO the biggest difference between stereo and mono subwoofers is level. If you are summing L + R to create your mono signal and the content in each channel is identical this will result in a +6 dB signal being sent to each subwoofer compared to stereo. This is definitely audible.

Michael

What’s that different to the sum being done at your ears?

 

[Sokel]

I will however happily allow for the fact that there may be lots of recordings out there that I'm not aware of that where one will detect significant differences between these configurations. Can you perhaps refer me to some?

Here is a good example:

Linn Records

Born of love for music and superlative sound, Scottish label Linn Records boasts an impressive catalogue packed with fine musicians from the worlds of classical, jazz and folk music. Since its launch in 1982, the label has constantly been striving for high-quality audio, from vinyl to building a...

www.linnrecords.com

Edit:It might be of interest what it takes to make such a recording.What is more surprising is the conditions that the engineers work,as Dr Toole said in another thread it's a miracle it sounds so beautiful:

Philip Hobbs & Linn Records: Recording The Dunedin Consort

When you make recordings designed to show off your hi-fi systems, they had better be good! It’s no accident that Philip Hobbs of Linn is one of the UK’s leading classical engineers and producers.

www.soundonsound.com

 

[mdsimon2]

What’s that different to the sum being done at your ears?

It sounds like more bass because it is more bass. I could easily see how someone could be tricked in to thinking summing the signal is filling in some null in their room because it sounds louder when in reality they are just sending a higher level signal to both subs.

Michael

 

[Prana Ferox]

You could do stereo subs with a Behringer DCX2496 or similar pretty easily (assuming your setup has preamp in/out on the mains)

I remain skeptical that it would matter, though. You could test this simply even with a mono signal if you have a way of playing test tones and having someone pan the level-matched signal between your subs while you have your eyes closed. I suspect trying this test with actual music muddies the results too much due to the harmonic content real music has.

 

[Sokel]

If I did it right,that's the info of the first track of the album (the one posted above) but please someone verify this is correct.
I shows significant differences between the channels down to 20Hz (L is red and R is blue):

 

[theREALdotnet]

You could test this simply even with a mono signal if you have a way of playing test tones and having someone pan the level-matched signal between your subs while you have your eyes closed. I suspect trying this test with actual music muddies the results too much due to the harmonic content real music has.

Even with a pure tone this is a difficult test to set up. I tried and found that (at least with the subs I can afford) you can still localise the sub, even though you cannot localise the sub-bass tone. Subs produce distortions and air noises and interact with the furniture around them, this tends to give them away. If you listen closely, even though you can tell which sub is playing, the sub-bass tone itself hangs in the air quasi location-less.

 

[sarumbear]

It sounds like more bass because it is more bass.

Enlighten me.

If there is equal bass tone on left and right speakers, you hear it at 6dB higher than if listening to one speaker. That’s because there are now two speakers emitting the same bass tone. When the two channels summed and fed to a single subwoofer the bass tone is also at that +6dB isn’t it?

The former is acoustic summation the latter is electronic.

I could easily see how someone could be tricked in to thinking summing the signal is filling in some null in their room because it sounds louder when in reality they are just sending a higher level signal to both subs.

I didn’t understand what you said.

 

[mdsimon2]

Enlighten me.

If there is equal bass tone on left and right speakers, you hear it at 6dB higher than if listening to one speaker. That’s because there are now two speakers emitting the same bass tone. When the two channels summed and fed to a single subwoofer the bass tone is also at that +6dB isn’t it?

The former is acoustic summation the latter is electronic.


I didn’t understand what you said.

I see that my point was unclear. I am starting from two subwoofers so when I said stereo vs mono I was referring to sending both subwoofers L+R (mono) vs sending one subwoofer L and one subwoofer R (stereo).

You exactly restated my point which is if you are sending L+R to a subwoofer that will be +6 dB compared to L or R alone. Therefore sending L + R with out decreasing the level by 6 dB will be louder.

Michael

 

[anotherhobby]

If I did it right,that's the info of the first track of the album (the one posted above) but please someone verify this is correct.
I shows significant differences between the channels down to 20Hz (L is red and R is blue):

View attachment 279058

I think this is a good example, at least to my ears — thanks for sharing! Listening to this on Tidal with stereo subs sounds more open and spacious to me. The mono sub configuration stacks up in the middle and feels less open and spacious. The mono bass sounds fine, but the stereo bass is noticeably better. Levels/curves are the same for both the stereo and mono configs.

 

[anotherhobby]

I see that my point was unclear. I am starting from two subwoofers so when I said stereo vs mono I was referring to sending both subwoofers L+R (mono) vs sending one subwoofer L and one subwoofer R (stereo).

You exactly restated my point which is if you are sending L+R to a subwoofer that will be +6 dB compared to L or R alone. Therefore sending L + R with out decreasing the level by 6 dB will be louder.

Michael

I set levels and delays with REW for each config, then corrected both to the same Dirac curve. Here are L/R channels measured back to back for both mono and stereo. There is no level difference mojo here, however I can see how somebody could not correctly set their levels and get a different result.

 

[Blumlein 88]

Here is an interesting artifact. I had a recording done with two spaced omnis 14 feet apart. When I filtered out everything above 80 hz, I had a bit of hum never noticed in one channel. When summed to mono, the 60 hz tone seemed to modulate the space something like comb filtering. Did not have that in stereo. I put in a notch filter at 60 hz with a Q of 8 and removed the hum in the one channel. Now there might, maybe have been a bit more spacious sound in stereo, but there was not a lot of difference. In this recording there were no musical instruments with any real output below 100 hz though it was done in a moderate sized church.

For most purposes I'd think the benefit of distributed bass for evening out room response swamps any benefit from stereo bass. I'd also think spaced omnis are going to be where you would find the most difference in stereo bass vs any other miking method. Such recordings are quite uncommon. I think we are down to really splitting hairs about this. Very, very few recordings even have a chance of it mattering.