Understood. But, usually today when Blumlein is mentioned, it is referring specifically to the coincident pair with figure-8s mike setup with corresponding speaker setup in playback.
BACCH-SP: The future of high-end audio? Yes.
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Understood. But, usually today when Blumlein is mentioned, it is referring specifically to the coincident pair with figure-8s mike setup with corresponding speaker setup in playback.
I think of him more to do with the 45 degree angle employed in the grooves of stereo LPs. He contributed a lot to how we do things today.
I agree entirely--I did not enjoy "Money" through the BACCH-SP. The effect of the BACCH-SP on recordings with soundfields created exclusively with pan knobs seems unpredictable, ranging from very impressive to intolerable.
I don't invest in high-end audio to listen to Pink Floyd (or any rock or pop music, with the exception of Beefheart), so that doesn't really bother me. The BACCH-SP was not created with byzantine recording studio mixes in mind. Indeed, the effect is best on binaural recordings, but conventional spaced omni recordings, including most commercially released recordings of classical music, sound incredible, too.
Crosstalk does not improve stereo imaging. Certain manufacturers of headphone amps and, eh, regrettably designed speakers have propagated this misinformation.
With respect to Prof. Choueiri's understanding of "human hearing perceptual rules," to dismiss his understanding of any of the principles involved is ludicrous. He's a member of the intellectual and engineering major leagues. Very few others who have recently designed products marketed to audiophiles are even in the minors. As one engineer-audiophile put it, "If it is built in Japan, audio equipment is designed by engineers who couldn't get jobs designing video equipment. If it is built in the US, audio equipment is designed by engineers who couldn't get jobs designing high frequency electronics or computers" (http://philip.greenspun.com/materialism/stereo). I think this is an understatement: some designers of "high-end" audio equipment aren't engineers at all.
I hope the market does adopt the BACCH-SP, but I worry that it won't for two reasons. First, the BACCH-SP does not accord with the conventional audiophile view that zero processing of sound is ideal. The BACCH-SP is a sophisticated computer, and it alters the signal between the source and the speakers. In a sense, however, the BACCH is an anti-processor: it partially eliminates the effect of putting speakers in a room, allowing the listener to get closer to the recording itself. The trouble is that most audiophiles probably won't see it that way.
Second, a lot of audiophiles listen primarily to music recorded in studios, and the BACCH-SP's effect on those recordings is inconsistent.
In any event, most of us who have heard it and who enjoy classical music think it's revolutionary. I hope it becomes a common sight in equipment racks.
Crosstalk, which I take to mean the degree to which each ear hears both speakers, is essential to stereo imaging. Blanket statements about increasing or decreasing crosstalk to improve stereo imaging cannot be applied generically since their value will depend on how the microphones were used during the recording process.
The crosstalk on the recording--i.e., sounds reaching both stereo microphones--is essential to imaging. The crosstalk added by placing speakers in a room is not essential and is in fact harmful to imaging.
I do agree that the recording process is relevant. The BACCH-SP clearly works best with binaural recordings. I listened to many spaced omni and Decca tree recordings on the BACCH-SP, and it works well with those recordings, too, even DG recordings with 900 spot mikes supplementing the stereo pair.
I have auditioned such several efforts from the old Fried M.A.R.S. and Polk SDA attempts and an acoustical Ambiophonic setup as well as the BACCH-SP (much the best of the bunch) and admit that they do open up and clarify the soundstage. However, those improvements have, so far, been accompanied by discomforting transitions to the extreme sides. None seem to achieve what one can hear from competently recorded/reproduced multichannel recordings.
Binaural recordings are, imho, irrelevant except as demos/experiments because there is no significant program content available commercially.
I have said it before in other places here, but the essential question is how much information is there on the stereo recording in the first place? I am of the belief that any stereo recording simply throws away much of the information about the recording venue because it cannot be reproduced accurately and convincingly by two speakers in a normal stereo setup. Stereo mixes that try to introduce too much hall sound generally sound cavernous, distant, and indistinct. So, much of the sound that ears actually heard at the live performance is simply discarded or severely attenuated in order for the recording to sound palatable in normal two speaker playback in the home.
In the hall, we hear much more reflected energy than direct energy. This was famously proven many decades ago by then MIT Professor Amar Bose, but it is a scientifically accepted finding, carefully peer reviewed, etc. However, Bose's own direct/reflecting speakers demonstrated the fallacy of trying to reproduce a live sense of music in the hall via only two frontal channels even with much energy also reflected into the room. That, of course, did not prevent him from making a gazillion dollars from the faulty concept.
There have been other failures of promising approaches that used 2channel as the starting point, like Blumlein miking, binaural miking, Carver Sonic Holography, etc., all as mentioned here. There are numerous other methods in common use today for multi-speaker-surround-from-two channel synthesis using Mch playback, like Dolby Pro Logic, DTS Neox, etc. The old Dynaquad also bears mention. But, they all suffer from the same problem: information is just not there on the stereo recording to fully recreate a sound field in the home that approaches what we hear live in the hall.
So, now we have a new, sophisticated and expensive "solution" to the problem, but no matter how sophisticated BACCH-SP is, it cannot overcome the same old problem. The information is just not there in stereo recordings. It has to guess, and no amount of crosstalk manipulation will put back what was not there, spectacular though the effect might be in early listening. I also thought Sonic Holography was spectacular when I first heard it, until I turned my head or moved my seat sideways by a foot or two.
I am 100% with Kal. The answer is to record more information than stereo via discrete mikes and multiple playback channels encompassing more of the angular space around your ears. We call that hi Rez Mch, and both he and I own thousands of recordings made that way. True, they are overwhelmingly classical, which makes them a niche. But, as Kal and I both know from going to many live classical concerts in good acoustic venues, this is as good as sound reproduction gets compared to live. And, $50,000 will buy you one hell of a nice complete hi Rez Mch music system.
I know it's an audio review bromide, but on the BACCH-SP, I heard a lot of information on stereo recordings, ones to which I'd listened hundreds of times, that I had never heard before. This is no exaggeration. The information is there, and the BACCH-SP, if it hasn't overcome the problem, represents a serious and partially successful attempt at solving it. I listened to it for almost six hours and never got sick of it.
I'm glad you've attended "many" live "classical concerts" in "good acoustic venues," but I've been to many hundreds of concerts, probably more than you and Dr. Rubinson combined. And I'm 30. If it happens that you've heard all of the world's great orchestras in almost all of the world's great halls (and with relatively young ears), we can have a who-knows-what-live-music-sounds-like debate.
Oh, but it does. You just have to hear it reproduced properly.
More microphones and more channels, I'm certain, will only exacerbate the problems of recording music in natural acoustic spaces.
I do not doubt at all your favorable listening impressions to BACCH. It may well be the biggest advance to date in better portraying a live sense of space from a 2 channel recording. And, I had no intention of getting into a pissing contest about who has gone to more concerts or has better hearing. My apologies for implying that.
What I am saying is the evidence for 360 degree, even top down hemispherical, hearing is quite well proven. If we hear a twig snap behind us in the forrest, we pretty well know where it is coming from. Although, for complete accuracy, our hearing is not equally as acute in all directions as it is to frontal sounds. It is also proven that much of our aural experience live in the concert hall comes from reflected energy from all around us, not just from the frontal direction.
Sound delivery into our listening rooms by two frontal channels alone simply cannot reproduce that completely surrounding and enveloping sense of space. Also, the directional information to the sides, rear and elevation in stereo has been stripped away, leaving little more than the front +- 30 or so degree horizontal window. Yes, stereo at its best can accomplish a bit more than that, placing some sounds somewhat left or right outside the speaker position triangle.
Properly done Mch addresses some of these issues with additional discretely miked speaker channels. The difficulties of doing this have been successfully met by quite a number of excellent recording teams who have been turning out very convincing hi Rez Mch classical recordings for the past dozen years or more on SACD, BD-A and BD-V. There are thousands of them.
Even so, stereo is geometrically a one dimensional system based on the line between the two speakers. It can also suggest a second phantom dimension of depth, much as a painting can suggest depth by the use of perspective. Mch starts with a two dimensional speaker layout, and it can also suggest depth, apply phantom imagining between the speakers, etc. in the same way as stereo. What is still missing from both currently is the third dimension of elevation or height. I do not know if something like Auro 3D will ever become a viable format for music, although one label, 2L, is already including the Auro format on its BD-A releases, which also include stereo and Mch.
In any case, I see BACCH as interesting and possibly better in many ways than traditional stereo. But, I also see its inherent limits by being tied to stereo recordings and playback. Mch today overcomes some of these limits quite successfully. I suggest that you try to give it a listen sometime on a well set up Mch system, which is not necessarily easy to find, even at dealerships. It is still a niche, but it appears to be well enough established and viable, mainly among classical music listeners.
Put simply its very obvious that you really don't know this for a fact. The manufacturer to which I referred did extensive demos at recent shows (RMAF in particular) turning the LCS drivers on an off, to show how the crosstalk did indeed improve imaging. Apparently you did not attend the demos.
I did often used to wonder how magnetic planers and ESLs could image as well as they do; upon doing some study I discovered why. In a nutshell: The human ear/brain system makes temporary copies of any sound it hears and then looks for similar sounds in the very near term. If it finds a similar sound it uses that information to help determine the source. Short-term echoes in a room caused by rear-firing information from a loudspeaker can take advantage of that capability in the human ear/brain system to improve imaging and depth. It would seem that either you or your professor simply don't know that yet.
Hmm. Then I am committing the ludicrous and isn't the first time nor will it be the last. If you really have represented him properly then simply put he has no idea of that which he speaks. It would not be the first time any of us have seen a highly educated person of great intelligence commit a very human mistake.
I'm going to give you an example of what I mean; seek out this recording and see what you think: Amused to Death (Acoustic Sounds will be reissuing the LP later this year) by Roger Waters. You can have plenty of crosstalk in the room and yet the encoding scheme on the LP (or CD) seems to work just fine! Yet as effective as that recording clearly demonstrates, its system too has failed to gain any wide acceptance. If you've not heard this recording you owe it to yourself to do so and no-one on this thread will argue this point if they have heard it.
I gained my EE and then went to work at Sperry Corp prior to their being bought out by Burroughs. However I had my own plans- my company was part time at that point and I left the computor industry to do it full-time. My colleagues thought I would never survive (I was 26 with a similar youthful arrogance that earned me plenty of bloodied noses and black eyes over the years) but somehow my company has survived over 38 years. I certainly agree that there is a lot of 'by gosh and by golly' going on in high end audio as many companies are operated by hobbyists, some of whom seem to be pretty clueless, but as a FWIW your comments appear insulting and also uneducated about the industry on the whole and border on trolling. IMO.
Another FWIW: 38 years is long enough to have seen similar ideas come and go. Now if your professor had suggesting an encoding method, abandoning conventional 2-channel altogether, I would think maybe he was on to something. But at least as far as your descriptions go, he seems to show a fundamental misunderstanding audio history and of how the human ear/brain system perceives sound; so appears to have set about to solve a problem that does not exist. IME this simply comes from not knowing how to set up a stereo properly, which is commonplace these days.
To me this is not as ludicrous as you suggest- I know people in the radio industry that broadcast stereo every day and yet don't know what stereo is really all about. If you talk to them about high end audio they think 'headphones' and that's it! So to me my viewpoint on the matter does not seem weird at all; just altogether too commonplace.
I go to many classical concerts at the Meyerson here in Dallas. All the sound is reflected unless I sat on the first row and at a piano concert. That's how it's designed.
I totally agree that there's much reflected sound off the ceiling of the concert hall. Here in Dallas we have a movable ceiling which is adjusted to the height which best suits the orchestral performance. So, it's always changing. Of course, the reflections are different depending on where one sits as well.
I have the utmost respect for classical musicians and their feedback is interesting when it comes to playback. However, they are always seated at a disadvantaged position when it comes to the complete work and how it sounds to the audience.
I really don't think we will ever get to the point of 100% reproducing classical works the way they sound live. But it's the pursuit of that which makes this hobby so much fun and the debates so interesting.
In my system I get a full 180 degree three dimension sound field. It's very real and palpable. That's what a really excellent stereo setup can do. And for me, that's happiness. I listen carefully at live classical performances sometimes for the reflected sounds which I perceive outside that 180 degree sound field I hear at home. I've concluded that very little comes to me consciously outside that field. Having said that, I don't ever claim that my system can perferctly reproduce what I hear in concert; nothing can do that.
I totally agree that there's much reflected sound off the ceiling of the concert hall. Here in Dallas we have a movable ceiling which is adjusted to the height which best suits the orchestral performance. So, it's always changing. Of course, the reflections are different depending on where one sits as well.
I have the utmost respect for classical musicians and their feedback is interesting when it comes to playback. However, they are always seated at a disadvantaged position when it comes to the complete work and how it sounds to the audience.
I really don't think we will ever get to the point of 100% reproducing classical works the way they sound live. But it's the pursuit of that which makes this hobby so much fun and the debates so interesting.
In my system I get a full 180 degree three dimension sound field. It's very real and palpable. That's what a really excellent stereo setup can do. And for me, that's happiness. I listen carefully at live classical performances sometimes for the reflected sounds which I perceive outside that 180 degree sound field I hear at home. I've concluded that very little comes to me consciously outside that field. Having said that, I don't ever claim that my system can perferctly reproduce what I hear in concert; nothing can do that.
I agree with one of your assertions--that we can hear sounds in three dimensions with two ears. But I disagree with the rest of your analysis because the BACCH-SP demonstrates conclusively that hearing in three dimensions from two-channel sources--especially from recordings made using only two microphones--is possible. The (mostly) two-dimensional "soundstage" that is audible between the speakers on a conventional stereo setup is supplanted in BACCH-SP-equipped systems by an entirely different spatial presentation. On most mainstream (i.e., multimiked) classical recordings, the main benefit is a palpable sense of perspective, with increased depth and elimination of the boundaries of the speakers with respect to the perceived width of the acoustic space (but not the performing ensemble). On recordings with minimal microphones or binaural microphones, the effect was more pronounced, and height cues were clearly audible.
Indeed, I'm curious to hear a really good multichannel system and am almost certain I've never heard one. (I did hear a megabuck Meridian multichannel setup once, but the room was ridiculously small for it.)
But I'm skeptical about multichannel for two a priori reasons. First, we only have two ears. Multichannel recordings tend to be made using very large microphone arrays, with microphones positioned in different parts of a hall. The results might be impressive and even evocative of the experience of listening to a concert, but I suspect that the effect is unlikely to be anything like what I hear from Row 2 at the Philharmonie.
Second, I think multichannel reproduction faces the same basic problem as conventional stereo playback: placing speakers in a room and in positions that sound good, but have no precise relation to what the recording engineer did, adds a host of acoustic artifacts that were not present on the original recording.
When I go to a concert, I listen with two ears. I'm interested in replicating that experience--to the extent possible--at home. By drastically reducing the acoustic distortions that occur when one listens to music through speakers that are in a room, the BACCH-SP represents a greater advancement toward replication of that experience than anything I've ever heard. I realize you have your own a priori reasons for skepticism about the BACCH-SP, but I hope you can try it.
Sorry for the long post, but I have to address each of Atmasphere's statements in turn.
No, I didn't. I have a rather intense job, and when I take time off, I tend to prefer hearing live music to attending audio shows. But here's why I'm fairly certain these LCS speakers are likely not to replicate the real experience: they use extra drivers to bounce midrange sound all over the room. This is unlikely to improve imaging (except perhaps in the utterly phony, sound bouncing all over the room, Amar Bose kind of way).
That's not why ESLs, ribbons, and other dipoles have wonderful imaging. The correct explanation can be gleaned from part of this presentation:
http://www.linkwitzlab.com/ALMA'14/Sound_quality.htm
And it seems that Prof. Choueiri is aware of the correct explanation because rumor has it that he uses electrostatic speakers in his own system.
I think we're on the same page here.
Amar Bose!
But Prof. Choueiri has not made a mistake. I urge you to read this paper: http://www.princeton.edu/3D3A/Publications/BACCHPaperV4d.pdf
The professor evidently knows what he's talking about, and his statements are totally consistent with what I heard from the BACCH-SP--to wit, that it sounds best on binaural recordings but effects extraordinary improvements on other stereo recordings made in natural acoustic spaces.
I don't understand--what's the encoding scheme?
This is irrelevant, but I'm happy that your company has survived and that you've been able to do something fun for so many years!
Telling the truth is never trolling. There are a few serious engineers in high-end audio, but I didn't intend to argue that mediocre engineers or non-engineers are incapable of making good stuff or making incremental improvements to existing technologies. I'm pretty sure not one piece of gear in my system was designed by someone with a PhD, and I really like my system.
I meant only that, finally, serious intellectual and research firepower was brought to bear on the problem of music reproduction. An entire lab studied this problem at Princeton University, and a breakthrough seems to have been the result. Without even listening to the device, some audio enthusiasts have dismissed not only the invention but also the professor's understanding of the principles involved.
This reaction is absurd but, sadly, was predicted by a BACCH-SP owner who, as a member of WBF, refuses to post in this thread for fear of being flamed.
I didn't know what stereo is all about until I heard those two BACCH-SP systems. I'll never view music reproduction the same way again.
No, I didn't. I have a rather intense job, and when I take time off, I tend to prefer hearing live music to attending audio shows. But here's why I'm fairly certain these LCS speakers are likely not to replicate the real experience: they use extra drivers to bounce midrange sound all over the room. This is unlikely to improve imaging (except perhaps in the utterly phony, sound bouncing all over the room, Amar Bose kind of way).
That's not why ESLs, ribbons, and other dipoles have wonderful imaging. The correct explanation can be gleaned from part of this presentation:
http://www.linkwitzlab.com/ALMA'14/Sound_quality.htm
And it seems that Prof. Choueiri is aware of the correct explanation because rumor has it that he uses electrostatic speakers in his own system.
I think we're on the same page here.
Amar Bose!
But Prof. Choueiri has not made a mistake. I urge you to read this paper: http://www.princeton.edu/3D3A/Publications/BACCHPaperV4d.pdf
The professor evidently knows what he's talking about, and his statements are totally consistent with what I heard from the BACCH-SP--to wit, that it sounds best on binaural recordings but effects extraordinary improvements on other stereo recordings made in natural acoustic spaces.
I don't understand--what's the encoding scheme?
This is irrelevant, but I'm happy that your company has survived and that you've been able to do something fun for so many years!
Telling the truth is never trolling. There are a few serious engineers in high-end audio, but I didn't intend to argue that mediocre engineers or non-engineers are incapable of making good stuff or making incremental improvements to existing technologies. I'm pretty sure not one piece of gear in my system was designed by someone with a PhD, and I really like my system.
I meant only that, finally, serious intellectual and research firepower was brought to bear on the problem of music reproduction. An entire lab studied this problem at Princeton University, and a breakthrough seems to have been the result. Without even listening to the device, some audio enthusiasts have dismissed not only the invention but also the professor's understanding of the principles involved.
This reaction is absurd but, sadly, was predicted by a BACCH-SP owner who, as a member of WBF, refuses to post in this thread for fear of being flamed.
I didn't know what stereo is all about until I heard those two BACCH-SP systems. I'll never view music reproduction the same way again.
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We only have two ears, but you are making a mistake with this thinking. Our ears don't create the sound. Whether you use two or 50 speakers to create the sound upon reproducing a recording you are listening again with two ears that didn't create what they are hearing. There is no direct reason, except in binaural headphone listening, to believe having two ears means two channels for playback is somehow inherently right. Seems inherently true if the original performance has some sound coming to your ears from behind, actually reproducing sound from behind you might ease creating the illusion of the original event.
Secondly, though I am sure almost any method has been used at least once in multi-channel recordings, I believe you would find much classical multi-channel recording is done with relatively compact trees of a few microphones. The Fukada tree is popular. There are several others. One other is double mid/side which is quite compact being a single point surround recording method.
Here is an AES paper from a decade ago about the matter. There have been quite a few such papers in the last 15 years.
https://www.academia.edu/7510241/Au..._BETWEEN_SURROUND-SOUND_MICROPHONE_TECHNIQUES
As a counterpoint, the Roger Waters recording mentioned on several good stereo systems can cause you (or at least me) to hear sounds quite clearly behind me or beside me or above me.
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I
Height reproduction from stereo or Mch systems without additional height channels is a very on again, off again thing that is highly playback system and room dependent. For example, speaker dispersion and ceiling reflections in the room play a big role regardless of the playback technology employed. I have heard excellent systems that could provide something of a vague suggestion of height, and others equally fine that do not. I would be most interested in any theoretical explanations Dr. Chouieri can provide of how his system can accurately recreate height information from a one-dimensional, two channel speaker array. Width and depth, yes. But, with height, I am highly skeptical. And, if height is heard, I would expect other factors to be at work, as described. It is at best an even more elusive phantom image than depth, in my view.
Ah, yes, the "I have only got two ears" fallacy. With headphones, yes, the two separate channels are one for one matched with each ear. But, with speakers, the omni directional response characteristic of each ear means that both ears are hearing all speakers all the time. And, each ear can hear sounds coming from different directions simultaneously, whether from stereo, Mch or Auro 3D. There is no one sound source to one ear correspondence at live concerts or when listening to speakers. That is the upshot of binaural hearing in humans.
In fact, at live concerts there is much, much more reflected sound reaching our ears omnidirectionally than there is direct sound. But, the direct sound predominates because it is spread over a much narrower angular window than the reflected sound - it is angularly more concentrated and perceived as louder than the more diffuse, higher levels of reflected energy - and it reaches our ears sooner than the reflected energy. The Haas Effect explains this perceived predominance. So, it is difficult, impossible even, to identify the presence of the reflected energy until you remove it, one reason music in a good hall is highly preferable to an outdoor concert. That is true not only spatially, but tonally, as well. The hall and its reflections play a major role in musical tonality.
A parallel: it is easy to see why man perceived that the sun revolved around the earth. That is how it appears to our senses. But, only scientific measurements beyond our unaided senses revealed that it was the other way around. Similarly, your ears and your unaided perception do not necessarily tell you the whole story of what is going on, as with direct and reflected sound.
Yet, the stereo recordings used by BACCH do not contain much of this reflected energy from the hall, as you would hear at your seat. Nor, do they contain any angular information beyond the direct and reflected energy from just the frontal soundstage. If it also captures reflected energy from other parts of the hall, it redirects it at you frontally - from the wrong angles. Stereo contains only partial information. Mch gathers and contains much more of the information one hears in the hall.
It is also quite an eye opener to switch from Mch to stereo in my room, as I am sure that BACCH on sounds quite different than off. However, I have fooled many a visitor to my room. They thought Mch was just very good stereo, until I switched to plain stereo. I have done this countless times with visitors, and no one yet has preferred the stereo or considered it truer to live sound. If you could get to Philly, I could easily demonstrate this.
Not all Mch recordings are, in fact, done with large arrays. Some are minimalist 5-mike setups, some do use multi-mike arrays. Many of the latter are quite successful, however. I say this as one who disliked the early DGG multi miked stereo intensely. The real issue was that old multi-miking with numerous directional spot mikes each captured just a small segment of the performers together with the small slice of space immediately around them. The resulting spatial cues in the stereo mix were therefore a confused hodgepodge of spatial segments, some overlapping. Mch mixing and mastering for classical music today is much more successful in recognizing this and achieving a more consistent overall sense of space and the performers within it, which is its objective. This multi-mike spatial issue is, by the way, a problem with the Dolby Atmos system in its attempts to move sound "objects" around the 3D soundstage. They carry their own locally recorded spatial cues around with them against the larger sense of space. But, that is movies, not music.
There is little confusion over speaker angular setup for Mch. The de facto standard is the 5-channel ITU angular arrangement used by well over 90% of classical recordings over the past dozen or so years. It is also true, by the way, that the center channel plays a very significant role. Its superiority to phantom center imaging, as in stereo, becomes quite apparent when playing remasterings of old Mercury or RCA 3 channel recordings vs. their 2 channel versions on the same SACD, as originally mastered for LP. There was a brief period in the '50's when stereo was conceived as 3-channel via mag tape, just before the invention of the 2-channel LP, disc cutters and stereo cartridges. The LP then could accommodate only 2 channels, a compromise we have lived with since then, unquestioned by most audiophiles.
Height reproduction from stereo or Mch systems without additional height channels is a very on again, off again thing that is highly playback system and room dependent. For example, speaker dispersion and ceiling reflections in the room play a big role regardless of the playback technology employed. I have heard excellent systems that could provide something of a vague suggestion of height, and others equally fine that do not. I would be most interested in any theoretical explanations Dr. Chouieri can provide of how his system can accurately recreate height information from a one-dimensional, two channel speaker array. Width and depth, yes. But, with height, I am highly skeptical. And, if height is heard, I would expect other factors to be at work, as described. It is at best an even more elusive phantom image than depth, in my view.
Ah, yes, the "I have only got two ears" fallacy. With headphones, yes, the two separate channels are one for one matched with each ear. But, with speakers, the omni directional response characteristic of each ear means that both ears are hearing all speakers all the time. And, each ear can hear sounds coming from different directions simultaneously, whether from stereo, Mch or Auro 3D. There is no one sound source to one ear correspondence at live concerts or when listening to speakers. That is the upshot of binaural hearing in humans.
In fact, at live concerts there is much, much more reflected sound reaching our ears omnidirectionally than there is direct sound. But, the direct sound predominates because it is spread over a much narrower angular window than the reflected sound - it is angularly more concentrated and perceived as louder than the more diffuse, higher levels of reflected energy - and it reaches our ears sooner than the reflected energy. The Haas Effect explains this perceived predominance. So, it is difficult, impossible even, to identify the presence of the reflected energy until you remove it, one reason music in a good hall is highly preferable to an outdoor concert. That is true not only spatially, but tonally, as well. The hall and its reflections play a major role in musical tonality.
A parallel: it is easy to see why man perceived that the sun revolved around the earth. That is how it appears to our senses. But, only scientific measurements beyond our unaided senses revealed that it was the other way around. Similarly, your ears and your unaided perception do not necessarily tell you the whole story of what is going on, as with direct and reflected sound.
Yet, the stereo recordings used by BACCH do not contain much of this reflected energy from the hall, as you would hear at your seat. Nor, do they contain any angular information beyond the direct and reflected energy from just the frontal soundstage. If it also captures reflected energy from other parts of the hall, it redirects it at you frontally - from the wrong angles. Stereo contains only partial information. Mch gathers and contains much more of the information one hears in the hall.
It is also quite an eye opener to switch from Mch to stereo in my room, as I am sure that BACCH on sounds quite different than off. However, I have fooled many a visitor to my room. They thought Mch was just very good stereo, until I switched to plain stereo. I have done this countless times with visitors, and no one yet has preferred the stereo or considered it truer to live sound. If you could get to Philly, I could easily demonstrate this.
Not all Mch recordings are, in fact, done with large arrays. Some are minimalist 5-mike setups, some do use multi-mike arrays. Many of the latter are quite successful, however. I say this as one who disliked the early DGG multi miked stereo intensely. The real issue was that old multi-miking with numerous directional spot mikes each captured just a small segment of the performers together with the small slice of space immediately around them. The resulting spatial cues in the stereo mix were therefore a confused hodgepodge of spatial segments, some overlapping. Mch mixing and mastering for classical music today is much more successful in recognizing this and achieving a more consistent overall sense of space and the performers within it, which is its objective. This multi-mike spatial issue is, by the way, a problem with the Dolby Atmos system in its attempts to move sound "objects" around the 3D soundstage. They carry their own locally recorded spatial cues around with them against the larger sense of space. But, that is movies, not music.
There is little confusion over speaker angular setup for Mch. The de facto standard is the 5-channel ITU angular arrangement used by well over 90% of classical recordings over the past dozen or so years. It is also true, by the way, that the center channel plays a very significant role. Its superiority to phantom center imaging, as in stereo, becomes quite apparent when playing remasterings of old Mercury or RCA 3 channel recordings vs. their 2 channel versions on the same SACD, as originally mastered for LP. There was a brief period in the '50's when stereo was conceived as 3-channel via mag tape, just before the invention of the 2-channel LP, disc cutters and stereo cartridges. The LP then could accommodate only 2 channels, a compromise we have lived with since then, unquestioned by most audiophiles.
Exactly the same as the other way around. It is indeterminate from just your unaided senses. But, biases, some religious, some not, tended to induce many to firmly believe the universe was geocentric for centuries. As we know, it was even at one point heresy to disbelieve that. It took more information via scientific inquiry than that which was immediately "obvious" to discover the truth.
The first place I recall hearing this effect is in Das Reingold, on Decca, Sir Georg Solti conducting. Side 6, near the end of the side, the Reinmaidens are lamenting the falseness of the gods. They were recorded (along with the harpists accompanying them) on a balcony overlooking the stage and that effect can be heard on a normal stereo, properly set up with good phase reproduction capacity. Apparently the recording engineers heard the same effect back in 1958 when it was recorded, as they commented on it at the time, documented in a book called Ring Resounding.
This is what I mean when I say there is a lack of grounding in the art that results in technology like this- a solution for something that isn't a problem.
I've operated a recording studio for about 35 years. What I suggest you do is get a set of decent microphones and go do a proper stereo recording. You go to lots of live venues so this should not be a problem. After a while you will sort out what mic placements work best depending on the musicians' layout and the nature of the venue itself. Then listen to your recordings- you will know how they are supposed to sound because you were there at the event itself. Now put one of those recordings through the professor's process and see if you still think its the cat's meow.
Not having heard them you have no idea what you are talking about, plain and simple, your midrange comment being a telling feature. Your Bose comment is nothing short of trolling. I never found Bose to image well FWIW.
The Bose comment is uncalled for and unwarranted
Really?? How can you be into your bag and not know this???
http://en.wikipedia.org/wiki/QSound
Go out and find a copy of Amused to Death and give it a good listen on a properly set up stereo. You will hear things that should not be able to happen according to your professor. Please cease and desist on commenting on this further until you have done this. Those who have the recording know exactly what I am talking about.
If you have ever heard of George Lucas, the reason his last 3 Star Wars films were so dreadful is that everyone working with him was afraid to tell him. He had such a stellar success with his prior films he apparently felt he could do no wrong and no-one wanted to point that out for fear of loosing their job. The result was dreck.
I heard an interview with this professor on NPR several years ago; I found myself shouting at the radio, mostly because the interviewer was taking him seriously. I don't contest that he knows his math, but the opening assumptions in his paper are actually the area where he gets in trouble, seemingly from a lack of grounding in the art. That was obvious at the time and and still seems to be the case from his paper. So he appears to have applied his talents to a problem that apparently only exists in junk stereos or systems with really poor set up. And maybe he's on to something for the masses where junk and poor setup are the norm. This forum is however devoted to high end audio where such is supposed to not be the case...
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