Preference Rating and the case for subjective preference

[thewas]

Multi-channel stereo is still a representation of the original soundfield with exactly the same limitations in regard to the main front channels.
The rear channels are there for the ambience, to create a more immersive experience and they must only contain reflected and reverberant sound information.

Which they do, while on stereo you only have random reflections of the direct sound depending on your room acoustics and loudspeaker placement and directivity.

 

[Sancus]

It depends on whether the goal is to document a live musical event (i.e. a cello concerto) or to create art in the mixing desk (i.e. a rock album).

1) If your goal is to document, stereo is inferior, on this we agree.

2) If your goal is to create, I STILL think stereo is inferior. Think about it: What is the benefit to "creating" a fake frontal-only sound field? There really isn't any. The goal of music created this way is still to create a "documented" experience, it's just being faked by the producer. The core belief that stereo is sufficient for this is typically that music is coming from in front of you, so that's all you need.

But this is an entirely artificial restriction, and real multi-channel music completely ignores the whole idea that music should be a frontal presentation AT ALL. For example, the famous quadrophonic recording of Pink Floyd's Dark Side of the Moon uses different sounds, including vocals as well as instrumental and non-instrumental sound mixed to all 4 channels at different points of the songs.

That experience is not even remotely frontal, and to me it's far more interesting than the vast majority of stereo recordings out there.

As I said above, # of channels is just a tool in the artist's palette. If you're documenting, being able to represent the reflections better is a benefit. If you're presenting, being able to put the listener in the middle of an experience that comes from all directions is a far more immersive and intense experience than a frontal one.

The biggest barrier is cost, but I don't agree that multi-channel will never catch on. There are hundreds if not thousands of multi-channel classical recordings out there, and people are consistently trying new things with it, up until today where there are a number of artists recording music for Atmos. Even some very famous ones are experimenting with it.

I think if the attempts at processing headphone audio to satisfying sound like surround speakers work out, the future may well be entirely object-based, multi-channel music. But who knows. Either way, it's definitely an interesting and useful tool for artists who want to create an experience for the listener.

 

[tuga]

Which they do, while on stereo you only have random reflections of the direct sound depending on your room acoustics and loudspeaker placement and directivity.

Yes, the advantage is that the rear channels can add some room cues and ambiance that are actually coming from the "right" place.

But they also take a lot of space, increase the system cost exponentially and may even cause destructive interference.

 

[tuga]

1) If your goal is to document, stereo is inferior, on this we agree.

2) If your goal is to create, I STILL think stereo is inferior. Think about it: What is the benefit to "creating" a fake frontal-only sound field? There really isn't any. The goal of music created this way is still to create a "documented" experience, it's just being faked by the producer. The core belief that stereo is sufficient for this is typically that music is coming from in front of you, so that's all you need.

But this is an entirely artificial restriction, and real multi-channel music completely ignores the whole idea that music should be a frontal presentation AT ALL. For example, the famous quadrophonic recording of Pink Floyd's Dark Side of the Moon uses different sounds, including vocals as well as instrumental and non-instrumental sound mixed to all 4 channels at different points of the songs.

That experience is not even remotely frontal, and to me it's far more interesting than the vast majority of stereo recordings out there.

As I said above, # of channels is just a tool in the artist's palette. If you're documenting, being able to represent the reflections better is a benefit. If you're presenting, being able to put the listener in the middle of an experience that comes from all directions is a far more immersive and intense experience than a frontal one.

The biggest barrier is cost, but I don't agree that multi-channel will never catch on. There are hundreds if not thousands of multi-channel classical recordings out there, and people are consistently trying new things with it, up until today where there are a number of artists recording music for Atmos. Even some very famous ones are experimenting with it.

I think if the attempts at processing headphone audio to satisfying sound like surround speakers work out, the future may well be entirely object-based, multi-channel music. But who knows. Either way, it's definitely an interesting and useful tool for artists who want to create an experience for the listener.

Rock and pop gigs use front sound only if I'm not mistaken.
Jazz clubs I've been to don't use surround channels either.

Surround can be used creatively in studio produced music but for what purpose? Most music is listened to over earbuds, TV or laptop speakers, even in mono on a smartphone...


P.S. multi-channel makes sense for classical because listeners tend to be more demanding and better off.

 

[thewas]

Rock and pop gigs use front sound only if I'm not mistaken.
Jazz clubs I've been to don't use surround channels either.

But in closed places gigs you have a high amount of reflected sound coming from usually the much more distant side and rear walls then in an usual listening room which you can't really replicate in stereo as your room dimensions are much smaller. In a good multichannel you can make your room very absorbent (which you shouldn't do in stereo as it needs the side wall reflections for the ambiance and envelopment) and have those real gig reflection sounds coming from the correct locations (and not just by random reflections) and with the correct level and delay.
Its all in Toole's book which I can only recommend everyone to read.

 

[tuga]

But in closed places gigs you have a high amount of reflected sound coming from usually the much more distant side and rear walls then in an usual listening room which you can't really replicate in stereo as your room dimensions are much smaller. In a good multichannel you can make your room very absorbent (which you shouldn't do in stereo as it needs the side wall reflections for the ambiance and envelopment) and have those real gig reflection sounds coming from the correct locations (and not just by random reflections) and with the correct level and delay.
Its all in Toole's book which I can only recommend everyone to read.

I disagree that stereo needs side wall reflections. They mess up the imaging and produce destructive interference.
And I'm not alone here.

But since most domestic sitting rooms are not very absorbent then narrow dispersion is preferable.

 

[thewas]

I disagree that stereo needs side wall reflections. They mess up the imaging and produce destructive interference.

If you listen to stereo in the most extreme case, i.e. a reflexionfree room of an acoustic lab it sounds very much like headphones creating an almost in-head-localisation, which you also get with extremely directive loudspeakers like big horns. Most people don't like that, if you do thats fine of course. The human hearing mechanism doesn't hear such interference (also not comb filtering), also stereo itself creates interference due to the cross talk between the channels and our ears but we don't hear it, its all again in Toole's book.

 

[edechamps]

And wouldn't the Haas effect justify the rating?

It looks like you still don't want to accept the idea that early reflections do have a specific effect on sound perception that is different and separate from the direct sound, even if the delay is lower than the precedence effect window. You might want to read Toole, Third Edition, sections 7.1 and 7.6.4 (the latter is literally titled "The Precedence (Haas) Effect"). Some excerpts:

Haas described this as an "echo suppression effect". Some people have mistakenly taken this to mean that the delayed sound is masked - it isn't. Within the precedence effect fusion interval, there is no masking; all of the reflected (delayed) sounds are audible, making their contribution to timbre and loudness, but the early reflections simply are not heard as spatially separate events. [...] The widely held belief that there is a "Haas fusion zone", approximately the first 20 ms after the direct sound, within which everything gets innocently combined, is simply not true.
[...]
The dominant audible effect of lateral reflection was spaciousness

In other words, the Haas effect is mostly about localization (as in, the specific direction the sound is perceived to come from), and should not be interpreted to mean anything about timbre, spaciousness, or any other aspect of perception. In fact, as quoted by Toole, Haas wrote that the effect came with a "pleasant broadening of the sound source". In other words, Haas himself subscribes to the idea that sounds arriving within the fusion interval are not masked nor simply mixed in the direct sound - they have their own separate perceptual effect.

The studies that are cited to support these claims are (this list might not be exhaustive):

• Benade, 1985: From Instrument to Ear in a Room: Direct or via Recording
• Olive & Toole, 1989a: The Detection of Reflections in Typical Rooms
• Clark, 1983: Measuring Audible Effects of Time Delays in Listening Rooms
• Haas, 1972: The Influence of a Single Echo on the Audibility of Speech
• Some obscure 1961 German study by Burgtorf

I disagree that stereo needs side wall reflections. They mess up the imaging and produce destructive interference.

As I alluded to in my Haas quote, that's another widespread myth that Toole busts in the same sections I cited. Side reflections have been shown by research to be beneficial more often than not. Toole likes to say that side reflections allow the brain to take a "second look" at the direct sound, enhancing our perception of it.

 

[thewas]

Toole likes to say that side reflections allow the brain to take a "second look" at the direct sound, enhancing our perception of it.

Yes, he is also showing that they can increase speech intelligibility.

 

[tuga]

It looks like you still don't want to accept the idea that early reflections do have a specific effect on sound perception that is different and separate from the direct sound, even if the delay is lower than the precedence effect window. You might want to read Toole, Third Edition, sections 7.1 and 7.6.4 (the latter is literally titled "The Precedence (Haas) Effect"). Some excerpts:



In other words, the Haas effect is mostly about localization (as in, the specific direction the sound is perceived to come from), and should not be interpreted to mean anything about timbre, spaciousness, or any other aspect of perception. In fact, as quoted by Toole, Haas wrote that the effect came with a "pleasant broadening of the sound source". In other words, Haas himself subscribes to the idea that sounds arriving within the fusion interval are not masked nor simply mixed in the direct sound - they have their own separate perceptual effect.

The studies that are cited to support these claims are (this list might not be exhaustive):

• Benade, 1985: From Instrument to Ear in a Room: Direct or via Recording
• Olive & Toole, 1989a: The Detection of Reflections in Typical Rooms
• Clark, 1983: Measuring Audible Effects of Time Delays in Listening Rooms
• Haas, 1972: The Influence of a Single Echo on the Audibility of Speech
• Some obscure 1961 German study by Burgtorf

As I alluded to in my Haas quote, that's another widespread myth that Toole busts in the same sections I cited. Side reflections have been shown by research to be beneficial more often than not. Toole likes to say that side reflections allow the brain to take a "second look" at the direct sound, enhancing our perception of it.

And by beneficial you mean someone's preference?
Some people even swear by omnis.
But others love horns or ESLs.

Reflections help to mask the location of the sources (speakers), widen the stage and increase "wetness". They also make images fuzzier and the "wetness" conflicts with the recorded ambience cues. It might work well with drier pop rock recordings but I don't find them at all advantageous for classical.

A room of mirrors.

 

[tuga]

If you listen to stereo in the most extreme case, i.e. a reflexionfree room of an acoustic lab it sounds very much like headphones creating an almost in-head-localisation, which you also get with extremely directive loudspeakers like big horns. Most people don't like that, if you do thats fine of course. The human hearing mechanism doesn't hear such interference (also not comb filtering), also stereo itself creates interference due to the cross talk between the channels and our ears but we don't hear it, its all again in Toole's book.

(It takes time to read that Bible.)

So, again, it's a matter of preference, of taste. Subjective. You can't impose a universal preference rating.

Thanks for inviting me to your new forum Amir. For my first post, allow me to refute the notion that early reflections are ever beneficial in a home-sized room:

Early Reflections



--Ethan

 

[tuga]

also stereo itself creates interference due to the cross talk between the channels and our ears but we don't hear it, its all again in Toole's book.

Have you tried physical or DSP crosstalk cancelation?

You can do it blind too, just be careful not to hit the partition with your nose and make sure that you are not listening to pink noise over a single speaker.

 

[thewas]

You can do it blind too, just be careful not to hit the partition with your nose and make sure that you are not listening to pink noise over a single speaker.

Due to my frequent nose injuries due to that setup I now moved to this one for crosstalk cancelation:

 

[ROOSKIE]

He addresses some of that in the study, he mentions that older listeners could prefer more treble due to age-induced hearing loss and that the female population was very small. I get your point but either way you still want to start with a neutral speaker and EQ to your tastes. Many of the passive speakers that have been measured so far are not just tonally shifted toward the bass or treble, but they have many resonances, peaks, dips, etc.

Having said that, I'm not saying the preference algorithm is perfect, if you've seen the double blind listening test of my LS50 vs Revel M105, you'll see that me and my girlfriend preferred the LS50 over the M105 even though the M105 measures much better. I still believe in the Science though because the M105 was still an amazing speaker and I could be happy with it as well.

Why wouldn't you just EQ the Revel to match you taste? If the point is to have a neutral speaker to EQ to taste, then now that you know you preferred the LS50 why not EQ the Revel to match it and keep the Revel?
I deeply love science as well. Hopefully you get my point here. I am not being clever.

 

[ROOSKIE]

1) If your goal is to document, stereo is inferior, on this we agree.

2) If your goal is to create, I STILL think stereo is inferior. Think about it: What is the benefit to "creating" a fake frontal-only sound field? There really isn't any. The goal of music created this way is still to create a "documented" experience, it's just being faked by the producer. The core belief that stereo is sufficient for this is typically that music is coming from in front of you, so that's all you need.

But this is an entirely artificial restriction, and real multi-channel music completely ignores the whole idea that music should be a frontal presentation AT ALL. For example, the famous quadrophonic recording of Pink Floyd's Dark Side of the Moon uses different sounds, including vocals as well as instrumental and non-instrumental sound mixed to all 4 channels at different points of the songs.

That experience is not even remotely frontal, and to me it's far more interesting than the vast majority of stereo recordings out there.

As I said above, # of channels is just a tool in the artist's palette. If you're documenting, being able to represent the reflections better is a benefit. If you're presenting, being able to put the listener in the middle of an experience that comes from all directions is a far more immersive and intense experience than a frontal one.

The biggest barrier is cost, but I don't agree that multi-channel will never catch on. There are hundreds if not thousands of multi-channel classical recordings out there, and people are consistently trying new things with it, up until today where there are a number of artists recording music for Atmos. Even some very famous ones are experimenting with it.

I think if the attempts at processing headphone audio to satisfying sound like surround speakers work out, the future may well be entirely object-based, multi-channel music. But who knows. Either way, it's definitely an interesting and useful tool for artists who want to create an experience for the listener.

I agree with your assessment that having more than two channels allows for a more complex experience.
I will say that despite that I am a 2-channel guy and I do not think it restricts creativity.
Just like color photography has a wider palate of real colors than B&W, in no way is one a substitute for the other, nor does one offer more creative potential. Creatively they are equal in potential.
In fact, I take that back a bit as I feel you often have to be more creative with B&W photography in order to make up for the missing bright colors.
Those bright colors captivate but they are often an excuse for using deeper creativity and for really getting to understand what makes a great subject, what makes great art.
In any case I love seeing what can be done with the limitation of just two speakers (not a mono guy though).

Additionally and maybe surprisingly to some, a part of the value for me in 2 channel audio comes from the lack of immersion. I want to be in my room, alone or with girlfriend. Siting there in front of my speakers watching and listening as the audio ghosts come and go imposing them selves on the features of my home. I want to dip from moments of immersion back to my room and the dimension of my reality - I don't ever actually want to be in a VR type environment. At some point somehow it comes full circle for me and actually feels fake/simulated. I guess I just don't like that. I want the immersion to meet me in my room, not take it completely away from me.

 

[QMuse]

Why wouldn't you just EQ the Revel to match you taste? If the point is to have a neutral speaker to EQ to taste, then now that you know you preferred the LS50 why not EQ the Revel to match it and keep the Revel?
I deeply love science as well. Hopefully you get my point here. I am not being clever.

EQ-ing both speakers to the same target before doing actual listening test is practically mandatory if you want to have serious comparison.

 

[Kal Rubinson]

Multi-channel stereo is still a representation of the original soundfield with exactly the same limitations in regard to the main front channels.
The rear channels are there for the ambience, to create a more immersive experience and they must only contain reflected and reverberant sound information.

Unless, there are more musicians back there. Of course, there rarely are any but that is not a limitation of the recording medium.

 

[thewas]

EQ-ing both speakers to the same target before doing actual listening test is practically mandatory if you want to have serious comparison.

I had done that in that in the past when I used my MK 1 JBL 305 as desktop monitors (now I use them in my living room as TV speakers) and without EQ I prefered the 305 as they have less tonal problems than the KEF LS50, but with EQ (both equalized to a flat direct sound) I preferred the LS50 as they sound kind of "cleaner", possibly also due to their much superior housings. Only at higher SPL levels the 305 sound better again as due to their larger woofer surface their intermodulation problems appear later.

 

[QMuse]

I had done that in that in the past when I used my MK 1 JBL 305 as desktop monitors (now I use them in my living room as TV speakers) and without EQ I prefered the 305 as they have less tonal problems than the KEF LS50, but with EQ (both equalized to a flat direct sound) I preferred the LS50 as they sound kind of "cleaner", possibly also due to their much superior housings. Only at higher SPL levels the 305 sound better again as due to their larger woofer surface their intermodulation problems appear later.

I hope all the folks that are evaluating/comapring speakers will read your post. It shows things are not that simple when both speakers have decent spinorama charts.

 

[thewas]

I agree, when the biggest problems of frequency response and directivity are solved and at an equal high level, then other secondary problems become the decisive factor.