Is Bass Better in Stereo? The Pros and Cons of Stereo Bass

S

shadyJ

Speaker of the House
Many audio enthusiasts are used to the idea that low bass frequencies are supposed to be monophonic in nature, but could there be advantages in having stereo bass much as stereo sound benefits the rest of the audible frequency range? Audio scientist Dr. David Griesinger believes so, and he is not without good reason to do so. We look at Dr. Griesinger's ideas about the advantages of stereo bass, and how it could potentially benefit the reproduction of music in audio systems. Read our article where we delve into the science of stereo bass.

READ: Is Bass Better in Stereo?
 
ryanosaur

ryanosaur

Audioholic Ninja
@Matthew J Poes !!!
Good to see you come out and play. :) Hope all is well with you and yours!
Cool read. Curious to know if this effect is better achieved in a larger or smaller room? Also, does the qty of low frequency sources assist or hamper this effect?

Cheers!
 
Matthew J Poes

Matthew J Poes

Full Audioholic
@Matthew J Poes !!!
Good to see you come out and play. :) Hope all is well with you and yours!
Cool read. Curious to know if this effect is better achieved in a larger or smaller room? Also, does the qty of low frequency sources assist or hamper this effect?

Cheers!
thanks @ryanosaur and as usual, I do apologize that I am not around more. I'm focusing my energy, as much as possible, on getting stuff off my plate. I currently am reviewing the JTR Noesis 110HT's and the Polk Audio Legend L800's, and I'm sure people will be excited to see these reviews publish.

The effect is likely more easily achieved in a larger room, but is achievable in any size room if setup correctly.

As for the second question, I guess I need to know what you are suggesting. If you mean, does turning up your subs assist or hamper, the answer is, it probably assists to a point. In a sense, its like turning the volume up on the effect. The information we use to perceive the spaciousness at low frequencies happens over a wide range of frequencies from as low as around 50hz to up into the 200-500hz range. Turning up the subs is only addressing about 1 octave of this information. It would also create a tonal imbalance that I don't think is necessary.

The best and easiest way to hear this is to, in my opinion, take a pair of subwoofers and place them on either side of you, hooked up in stereo, and balanced correctly. Operate them in parallel to the mains, meaning that the mains still operate full range, such that the subs overlap the mains a lot. Cross the subs at something like 100hz. You might even try higher, 150hz for example, to see if bass becomes localizable or not. If not, this might further enhance the effect. The subwoofers do not necessarily need to be identical to experiment with this, as long as they are not wildly different. If they produce a similar flat response down to 50hz and can be leveled out similarly, you should be ok.

I have some contrived test tones that allows you to hear the effect, along with a playlist. I just need to get permission to share this (likely the playlist is not a concern, but the contrived tracks are not mine to share). To hear the effect, you really need to be able to switch the bass from stereo to mono, it is very subtle. Once you know what you are looking for you will notice it.

I think its importance is personal. It's impossible to say one is more right than another. It is certainly true that stereo bass or bassiousness is more accurate to the original event for real live performances. The problem is, how often do we hear real live performances in that way? Queen's albums are often encoded correctly for this effect and its audible, but they were an arena rock band, what stereo bass existed in the original performance? None! What we are recreating is an effect added by the Lexicon reverb unit. Is the reproduction of stereo bass truer to the source and intent of the original engineer and artists? Who knows? Like I've said with other aspects of spatial music reproduction, we know its critical to the accurate reproduction of classical symphonic performances and something like small live jazz performances. Any time we get into studio recordings or amplified music, the original intent becomes a guessing game. I've made clear that I find spatial aspects of music reproduction critical to my enjoyment, and its an extension of my obsession with imaging/soundstaging. However, when it came to this, The effect was not as dramatic and difficult to achieve, so I ended up giving up on it. However, I loved learning about it and I have made it's implementation a part of my setup tool belt. I think, in the end, people just need to try it and decide for themselves.
 
Pogre

Pogre

Audioholic Spartan
thanks @ryanosaur and as usual, I do apologize that I am not around more. I'm focusing my energy, as much as possible, on getting stuff off my plate. I currently am reviewing the JTR Noesis 110HT's and the Polk Audio Legend L800's, and I'm sure people will be excited to see these reviews publish.

The effect is likely more easily achieved in a larger room, but is achievable in any size room if setup correctly.

As for the second question, I guess I need to know what you are suggesting. If you mean, does turning up your subs assist or hamper, the answer is, it probably assists to a point. In a sense, its like turning the volume up on the effect. The information we use to perceive the spaciousness at low frequencies happens over a wide range of frequencies from as low as around 50hz to up into the 200-500hz range. Turning up the subs is only addressing about 1 octave of this information. It would also create a tonal imbalance that I don't think is necessary.

The best and easiest way to hear this is to, in my opinion, take a pair of subwoofers and place them on either side of you, hooked up in stereo, and balanced correctly. Operate them in parallel to the mains, meaning that the mains still operate full range, such that the subs overlap the mains a lot. Cross the subs at something like 100hz. You might even try higher, 150hz for example, to see if bass becomes localizable or not. If not, this might further enhance the effect. The subwoofers do not necessarily need to be identical to experiment with this, as long as they are not wildly different. If they produce a similar flat response down to 50hz and can be leveled out similarly, you should be ok.

I have some contrived test tones that allows you to hear the effect, along with a playlist. I just need to get permission to share this (likely the playlist is not a concern, but the contrived tracks are not mine to share). To hear the effect, you really need to be able to switch the bass from stereo to mono, it is very subtle. Once you know what you are looking for you will notice it.

I think its importance is personal. It's impossible to say one is more right than another. It is certainly true that stereo bass or bassiousness is more accurate to the original event for real live performances. The problem is, how often do we hear real live performances in that way? Queen's albums are often encoded correctly for this effect and its audible, but they were an arena rock band, what stereo bass existed in the original performance? None! What we are recreating is an effect added by the Lexicon reverb unit. Is the reproduction of stereo bass truer to the source and intent of the original engineer and artists? Who knows? Like I've said with other aspects of spatial music reproduction, we know its critical to the accurate reproduction of classical symphonic performances and something like small live jazz performances. Any time we get into studio recordings or amplified music, the original intent becomes a guessing game. I've made clear that I find spatial aspects of music reproduction critical to my enjoyment, and its an extension of my obsession with imaging/soundstaging. However, when it came to this, The effect was not as dramatic and difficult to achieve, so I ended up giving up on it. However, I loved learning about it and I have made it's implementation a part of my setup tool belt. I think, in the end, people just need to try it and decide for themselves.
So send left and right stereo to the respective subs and mains full range and use the LP filter on the sub to blend with speakers?

*Edit: That would be pretty easy the way I'm set up I think. My subs are both up front in a stereo config.

20190930_111120-816x459.jpg
 
Matthew J Poes

Matthew J Poes

Full Audioholic
So send left and right stereo to the respective subs and mains full range and use the LP filter on the sub to blend with speakers?

*Edit: That would be pretty easy the way I'm set up I think. My subs are both up front in a stereo config.

View attachment 33555
Yes but your subs are in the wrong place. You need to move them to the sides of the room as I depict in the article. On either side of you.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Spartan
I have to go back and read it when I get time tonight as I only could skim the story. But I wonder if a different title might be appt. Reason is, and I will delete this if I’m talking out of turn, naturally. Tom noussaine did a pretty deep dive on “stereo bass”. In a small nutshell, he found that there was almost no content with stereo bass encoded into it, and it it very effective, or at the very least, not worth any effort. Something happened a few years ago after he passed away, and now(unless I don’t know where to look) it’s impossible to find any of his older work. He was brilliant, and a great contributor.
Again, if I’m upside down, I’ll gladly say so. Just wondered if you knew anything about toms version.
 
TLS Guy

TLS Guy

Audioholic Slumlord
This is quite provocative. I have always been aware that good bass reproduction does add spaciousness to reproduction and I don't think we really understand why. Gilbert Briggs founder of Wharfedale pointed this out as early as the fifties. I have found that to be true. Systems that lack bass extension are generally not as spacious as ones that have good bass extension. Although boomy or poorly balanced bass ruins the effect.

I did note that in my last room running LFE plus mains was better then a full crossover.

Here Audyssey wanted to set the mains to large and cross the others over at 40 Hz except the ceiling speakers and surrounds.

Anyhow I ended up setting the crossover to the shorter line at 40 Hz and setting the bass crossover to the large lines a 40 Hz. Of course this limited the baffle step compensation to 40 Hz also. This is because I have a mixing circuit that blends the sub output and baffle step compensation to the upper 10" drivers in the long lines. The sub output and LFE is fed to all the 10" drivers in the long bass lines. The system is very flat down to 20 KHz.

I eventually came to the conclusion that the reproduction was not quite as spacious as previously, so I have set the left and right mains to LFE + main at 40 Hz. I do think this is more spacious. Now part of this may be better phase alignment as there is now only 90 degrees of phase shift at the 40 Hz crossover.

The other issue about spaciousness is that the effect is lost with speakers too close together. That is a really common fault in set up. I believe 8 ft is about as close as you ever want the right and left speaker is best and 10 to 12 ft optimal if the room allows.

One thing that really stands out about this rig is that it is spacious.

Unfortunately there are very few really good truly full range speakers around that are low Q and essentially non resonant with minimal phase shift with the drivers in good time alignment to widely investigate these issues. This system is totally unique with nothing else quite like it that I am aware.

One thing I can tell you is that I do not have a problem with uneven bass. It is very uniform throughout the room

I do believe that a well aligned full range speaker actually does best scattering subs around the place.
 
TLS Guy

TLS Guy

Audioholic Slumlord
I have to go back and read it when I get time tonight as I only could skim the story. But I wonder if a different title might be appt. Reason is, and I will delete this if I’m talking out of turn, naturally. Tom noussaine did a pretty deep dive on “stereo bass”. In a small nutshell, he found that there was almost no content with stereo bass encoded into it, and it it very effective, or at the very least, not worth any effort. Something happened a few years ago after he passed away, and now(unless I don’t know where to look) it’s impossible to find any of his older work. He was brilliant, and a great contributor.
Again, if I’m upside down, I’ll gladly say so. Just wondered if you knew anything about toms version.
Yes, I was aware of his work. It would be surprising if you found differences in intensity studying the bass of two channel stereo. However I suspect if you looked you would find changes in phase relationships. It is not fashionable to contend that phase and time relationships (they are the same thing) matter. However my experience is to the contrary. I do believe they matter especially in this arena. The reason is simple as almost all speakers crucify phase relationships. So often trying to put that right creates far worse ills. So that makes all this very difficult.
 
Matthew J Poes

Matthew J Poes

Full Audioholic
I have to go back and read it when I get time tonight as I only could skim the story. But I wonder if a different title might be appt. Reason is, and I will delete this if I’m talking out of turn, naturally. Tom noussaine did a pretty deep dive on “stereo bass”. In a small nutshell, he found that there was almost no content with stereo bass encoded into it, and it it very effective, or at the very least, not worth any effort. Something happened a few years ago after he passed away, and now(unless I don’t know where to look) it’s impossible to find any of his older work. He was brilliant, and a great contributor.
Again, if I’m upside down, I’ll gladly say so. Just wondered if you knew anything about toms version.
I actually provide proof of stereo bass in the article. I made a similar comment to David about this idea and he retorted that this was simply not true. I then investigated a dozen or more songs and found that there is in fact quite a bit of musical content with stereo bass.

I do also say in the article that there is not a majority of modern pop music in stereo bass however. So both are true. It’s worth is more up to you. Content exists, even really old pop/rock (Queen for example), but it is not the norm. Amongst classical music a lot more exists. Of the classical performances I checked, all of them contained stereo bass.

I could probably provide examples of stereo bass by song here in the forum. I checked many and could share the images. I kept them out of the article for simplicity. The way I did this was by recording a track, low passing it at various frequencies (200hz, 100hz, 80hz, and 50hz) and then analyzing the stereo content. I normalized the levels because there is less content in general as you get lower causing the phase cloud to shrink. Normalizing helps keep things even. Basically what you look for is a round fluffy cloud verse a cat eye shape in the phase plot. Modern pop was basically a cat eye below 100hz in nearly everything I tried. But lots of music I tested did show that round shape. I suspect there is probably a kind of logic or formula you could use to figure out which recordings have stereo bass.

as noted in the article, anything mastered with the lexicon reverb unit and not molested after will likely have stereo bass. It’s my understanding that it would lot have been common to sum the bass to mono as routine. It was usually done for a reason. A mono reverb unit was one reason, as part of the final mix for a record album was another (though David points out that this too isn’t always true and again points to Queen as an counter-example). I’ll be honest in saying I didn’t look at any records in my research for this article.

the shorter answer is that stereo bass exists, it’s not a unicorn, there is actually quite a bit of content (even if it’s not the norm), and I have no idea what Tom looked at and how valid it was then or is today. All I know is what I found.
 
Matthew J Poes

Matthew J Poes

Full Audioholic
This is quite provocative. I have always been aware that good bass reproduction does add spaciousness to reproduction and I don't think we really understand why. Gilbert Briggs founder of Wharfedale pointed this out as early as the fifties. I have found that to be true. Systems that lack bass extension are generally not as spacious as ones that have good bass extension. Although boomy or poorly balanced bass ruins the effect.

I did note that in my last room running LFE plus mains was better then a full crossover.

Here Audyssey wanted to set the mains to large and cross the others over at 40 Hz except the ceiling speakers and surrounds.

Anyhow I ended up setting the crossover to the shorter line at 40 Hz and setting the bass crossover to the large lines a 40 Hz. Of course this limited the baffle step compensation to 40 Hz also. This is because I have a mixing circuit that blends the sub output and baffle step compensation to the upper 10" drivers in the long lines. The sub output and LFE is fed to all the 10" drivers in the long bass lines. The system is very flat down to 20 KHz.

I eventually came to the conclusion that the reproduction was not quite as spacious as previously, so I have set the left and right mains to LFE + main at 40 Hz. I do think this is more spacious. Now part of this may be better phase alignment as there is now only 90 degrees of phase shift at the 40 Hz crossover.

The other issue about spaciousness is that the effect is lost with speakers too close together. That is a really common fault in set up. I believe 8 ft is about as close as you ever want the right and left speaker is best and 10 to 12 ft optimal if the room allows.

One thing that really stands out about this rig is that it is spacious.

Unfortunately there are very few really good truly full range speakers around that are low Q and essentially non resonant with minimal phase shift with the drivers in good time alignment to widely investigate these issues. This system is totally unique with nothing else quite like it that I am aware.

One thing I can tell you is that I do not have a problem with uneven bass. It is very uniform throughout the room

I do believe that a well aligned full range speaker actually does best scattering subs around the place.
If you want to understand why, take a look at my references. I think we clearly understand why at this point. David has done a great job explaining the mechanism.

Basically, as we move lower in frequency below a certain point (say 1khz) we rely more and more on the interaural time difference (ITD) and less and less on interaural level difference (ILD). By 200hz or so we do not use ILD at all. Our perception of space is largely a function of envelopment or the sense of reflections from all around us. The delay in those reflections provided critical information on the size of a room. Something a small domestic room can’t mimic that well (that is a small domestic room can’t recreate the delay we would see in an actual performance space). At low frequencies the size of the wavelengths is so large that the impact on spatial perception is a little different. We detect the size of the room and location of a sound source as outside our head and in a room in a grosser manner. Things like the lateral time difference of the low frequencies. If we think of bass as pressure in the room, then we can think of it as a kind of pressure difference that is created. This pressure difference can be interpreted by our brain as a sign that the source is outside of us in the room. Without it, it’s not clear to our brain where it is so the constant and uniform pressure change of a mono bass system just sounds the same as if we listened on headphones. Bass in our head.

Our perception of the the space in which a performance takes place and the relationship between that space and the sound source relies on many cues which are frequency dependent. At low frequencies things become very simple. Only lateral separation really matters (but significant lateral separation becomes ideal).

I think the article probably implied that a stereo bass system cannot have smooth bass and that was probably too strong. Certainly an optimized room might achieve this without multiple subs. It isn’t true to say all rooms always have uneven bass throughout the room. Most rooms certainly. Optimizing the acoustics and room ratio can go a long way. I’ve also seen systems that develop planar waves and ultimately the effect of longitudinal modes is of little consequence with lateral modes strong and vertical modes canceled. This would probably lead to a good sounding system where possible. The problem? How many people have stereo vertical bass arrays with maximum separation.

in any case I am glad you liked the article. It did seem like a topic you would have enjoyed. I know these topics can feel a little esoteric to some. I think they are an important part of How we can collectively understand how good sound reproduction is achieved. I don’t mind people disagreeing with my world view on good sound. I just prefer everyone to at least work off the same basic facts.
 
Bizarro_Stormy

Bizarro_Stormy

Audioholics Whac-A-Mole'er™
You're right, bass sounds much better in stereo... but it smells much worse...

4044016.jpg
 
William Lemmerhirt

William Lemmerhirt

Audioholic Spartan
I actually provide proof of stereo bass in the article. I made a similar comment to David about this idea and he retorted that this was simply not true. I then investigated a dozen or more songs and found that there is in fact quite a bit of musical content with stereo bass.

I do also say in the article that there is not a majority of modern pop music in stereo bass however. So both are true. It’s worth is more up to you. Content exists, even really old pop/rock (Queen for example), but it is not the norm. Amongst classical music a lot more exists. Of the classical performances I checked, all of them contained stereo bass.

I could probably provide examples of stereo bass by song here in the forum. I checked many and could share the images. I kept them out of the article for simplicity. The way I did this was by recording a track, low passing it at various frequencies (200hz, 100hz, 80hz, and 50hz) and then analyzing the stereo content. I normalized the levels because there is less content in general as you get lower causing the phase cloud to shrink. Normalizing helps keep things even. Basically what you look for is a round fluffy cloud verse a cat eye shape in the phase plot. Modern pop was basically a cat eye below 100hz in nearly everything I tried. But lots of music I tested did show that round shape. I suspect there is probably a kind of logic or formula you could use to figure out which recordings have stereo bass.

as noted in the article, anything mastered with the lexicon reverb unit and not molested after will likely have stereo bass. It’s my understanding that it would lot have been common to sum the bass to mono as routine. It was usually done for a reason. A mono reverb unit was one reason, as part of the final mix for a record album was another (though David points out that this too isn’t always true and again points to Queen as an counter-example). I’ll be honest in saying I didn’t look at any records in my research for this article.

the shorter answer is that stereo bass exists, it’s not a unicorn, there is actually quite a bit of content (even if it’s not the norm), and I have no idea what Tom looked at and how valid it was then or is today. All I know is what I found.
“All I know is what I found”. Well said.
After a read(watch the video later) it seems my initial expectation was “stereo bass” as how you described the movement of bass similar to what we’re used to in normal stereo listening. Iirc, that’s what Tom was investigating.
I probably have enough gear laying around to try this out, but probably not time. It seems like while the effect is super cool, it’s content dependent and might not be worth it for many of us. I don’t know if it’s related, or unrelated but I’ve always felt that subs with deep extension capabilities can somehow add to, borrowing your term, bassiousness. I’m very lucky in that my main system extends to about 14hz. Listening to music there, vs other systems I’ve heard, and own it just seems to have more scale and weight. Even with bands like Boston, or Rush that don’t extend, let alone modern ones that put more effort there. I’ve never truly known what to attribute the feeling to, my gut said it was the subs, and possibly sub harmonics. Side road, sorry...squirrel!!!

Anyway, thanks for sharing something different. Nice to read something that’s NOT dogma, out of the box and unexpected. Btw, links are always fun.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Yes but your subs are in the wrong place. You need to move them to the sides of the room as I depict in the article. On either side of you.
Yes, but that is a huge problem. That is a highly inconvenient place to put subs, and few wives would put up with it. If I did that, one would be right in front of my DAW desk and so I could not get to it, nor could I get passed the second row of seats. The sub on the other side would stop me getting passed the the other side of the second row of seats and make the rear of the room inaccessible!

None of the three rooms in which I have sound systems could possibly tolerate subs either side of the seating position.

Now I have been doing this now for over 60 years. I have never had all the problems you people have getting good and even bass throughout any room I have placed sound systems, and that is a lot. The bass has always come from the area of the main speakers. Until 14 years ago it was only two channel stereo and actually before 1959 just one channel.

I just don't have all these problems you guys claim to have getting accurate bass though out the room. Certainly nothing of the level that would require making our living spaces look ridiculous.

So I have a feeling there are a lot of speakers on the market that are not properly tuned contributing to all these problems. Part of the reason I suspect is that I have used almost exclusively pipes for bass reproduction.
 
Jon AA

Jon AA

Junior Audioholic
Thanks Matthew, that was a great discussion/article. I'd be really interested to get your thoughts on how this may apply to multi-channel setups--as we know action movies don't just have Stereo Bass effects, but Surround Bass effects.

Paul Hales calls it "local bass management" and is a big advocate for it. In simplistic terms, subs are located around the room and speakers are bass managed to the nearest sub, instead of a single mono signal going to all subs. LFE goes to all subs, but a higher level to the subs in front as that's where most of the action is.

The benefits he describes seem to be the same principles that many say they enjoy with stereo bass--just taken to the next level with multi-channel.

His basic premise is that short, violent transients (kick drum, timpany, bang of a gun/explosion, etc) are localizable to much lower frequencies than a steady-state sine wave or the like is.

In his own words:


In that he mentions the idea at about 52 minutes.


In that one 25 minutes and 34 minutes and goes into more detail about the setup at 1:11 (for those who don't want to watch the whole things--though I'd encourage people to do so as one can learn a lot from that guy).

I heard him mention this concept in one of those years ago and it has fascinated me ever since. Unfortunately, it's not something the average guy can give a try without spending a lot (you basically need a Trinnov or SDP-75 to do what he's talking about).

Anyway, since you've done a bunch of experimentation with two channels, I was curious how you think that may apply to multi-channel. Maybe you can get Gene to buy you a Trinnov so you can test it and write a followup. :)
 
Pogre

Pogre

Audioholic Spartan
Yes but your subs are in the wrong place. You need to move them to the sides of the room as I depict in the article. On either side of you.
Whaaat?? Read the article?!

:p

J/K. I finished it up last night. Looks like a fun experiment at the least, but not very practical for my room.
 
DeSteen_Septon

DeSteen_Septon

Audiophyte
When I purchased my first 5.1 Sony receiver I had a long conversion with Sony rep that the .1 channel was killing the separation on some of my records e.g. New Order "Blue Monday" there is some < 30 hertz bass notes that are recorded far left / far right. He promptly told me that it was impossible to localize bass frequencies below 40 hertz. I cited recordings. He said they weren't movies . I thanked him for his help and hung up. Recently I purchased a sub-woofer for my JBL 3 series studio speakers and it completely killed the opening guitar riff of [the smiths] "How soon is Now" So I am of the opinion that you need stereo sub-woofers.. Thank you very much for writing this
 

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