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Hi-fi, High-end and Multi-channel reproduction
As a choral singer, I regularly have the opportunity to hear what is
frequently referred to as the "absolute sound", namely unamplified music in a concert hall. As regards this reference, we audiophiles frequently question whether the purpose of a reproduction system is to recreate the original musical experience in the listening room, or whether it is to reproduce what the recording engineer heard in the control room. Recently during a rehearsal at Weil Recital Hall at Carnegie while waiting to get on stage, I was sitting in the third row of the mostly empty hall listening to a sonata for piano and cello and trying to figure out (seemingly for the zillionth time) what it was that allows the ear to so clearly distinguish even the finest quality reproduced music from the real thing. While the obvious factors such as tonal balance and dynamic range certainly contribute, I began to reconsider (again, for the zillionth time) the role that ambient sound plays. As I listened, it ocurred to me that the percentage of reflected sound to direct was probably much greater than I had previously thought (bearing in mind that while I was in row 3, the hall was mostly empty) and that the quality and quantity of reflected sound probably has as much to do with the subjective impression of "live or memorex" as does the traditionally thought of factors of tonal balance and dynamic range. Back to the original question. I have always been of the opinion that an accurate replay of the control room is all that could be hoped for, and that assuming the engineer did his job properly, a reasonable facsimile of the original event could be had. (The thinking was based in part on the concept that no listening room could be made to acoustically duplicate a concert or recording venue. This also happens to be the thinking that led to binaural recording & playback techniques.) Which brings us to the possibility that discreet multi-channel playback should be far more capable of reproducing the original acoustic space than stereo ever could hope to. This is so obvious and self-evident that I have difficulty understanding why the audiophile community continues to disparage multi-channel systems as being good for movies only. That stereo is physically incapable of placing sound behind (and to the sides of, etc.) the listener is obvious. That to accurately replicate an acoustic event requires sounds (a potentiallysignificant portion of the total sound as previously discussed) to be located behind the listener is equally obvious. The simple fact is that a concert cannot be accurately reproduced with sounds emanating only from in front of the listener. It's just not what we ever hear in the original venue. When viewed from this standpoint, even if DVD-A and SACD provide no more "resolution" in two channels than standard red-book CDs, the potential for a more accurate reproduction of the original musical event via a multi-channel experience should have all audiophiles jumping at those formats. Rather than quibbling over interconnects and speaker cables with all their limited (if at all existing) possibilities for improvement, I suggest that a far more meaningful upgrade would be the addition of 2 or 3 channels to existing systems. Save for speaker upgrades, we really have maxed out the capabilities of the stereo format. It is only through multi-channel playback that we can hope to approach a true recreation of the "absolute sound." Bruce |
#2
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Hi-fi, High-end and Multi-channel reproduction
"Bruce Abrams" wrote in message
... As a choral singer, I regularly have the opportunity to hear what is frequently referred to as the "absolute sound", namely unamplified music in a concert hall. As regards this reference, we audiophiles frequently question whether the purpose of a reproduction system is to recreate the original musical experience in the listening room, or whether it is to reproduce what the recording engineer heard in the control room. Recently during a rehearsal at Weil Recital Hall at Carnegie while waiting to get on stage, I was sitting in the third row of the mostly empty hall listening to a sonata for piano and cello and trying to figure out (seemingly for the zillionth time) what it was that allows the ear to so clearly distinguish even the finest quality reproduced music from the real thing. While the obvious factors such as tonal balance and dynamic range certainly contribute, I began to reconsider (again, for the zillionth time) the role that ambient sound plays. As I listened, it ocurred to me that the percentage of reflected sound to direct was probably much greater than I had previously thought (bearing in mind that while I was in row 3, the hall was mostly empty) and that the quality and quantity of reflected sound probably has as much to do with the subjective impression of "live or memorex" as does the traditionally thought of factors of tonal balance and dynamic range. Back to the original question. I have always been of the opinion that an accurate replay of the control room is all that could be hoped for, and that assuming the engineer did his job properly, a reasonable facsimile of the original event could be had. (The thinking was based in part on the concept that no listening room could be made to acoustically duplicate a concert or recording venue. This also happens to be the thinking that led to binaural recording & playback techniques.) Which brings us to the possibility that discreet multi-channel playback should be far more capable of reproducing the original acoustic space than stereo ever could hope to. This is so obvious and self-evident that I have difficulty understanding why the audiophile community continues to disparage multi-channel systems as being good for movies only. That stereo is physically incapable of placing sound behind (and to the sides of, etc.) the listener is obvious. That to accurately replicate an acoustic event requires sounds (a potentiallysignificant portion of the total sound as previously discussed) to be located behind the listener is equally obvious. The simple fact is that a concert cannot be accurately reproduced with sounds emanating only from in front of the listener. It's just not what we ever hear in the original venue. When viewed from this standpoint, even if DVD-A and SACD provide no more "resolution" in two channels than standard red-book CDs, the potential for a more accurate reproduction of the original musical event via a multi-channel experience should have all audiophiles jumping at those formats. Rather than quibbling over interconnects and speaker cables with all their limited (if at all existing) possibilities for improvement, I suggest that a far more meaningful upgrade would be the addition of 2 or 3 channels to existing systems. Save for speaker upgrades, we really have maxed out the capabilities of the stereo format. It is only through multi-channel playback that we can hope to approach a true recreation of the "absolute sound." Bruce Bruce, I agree with you completely on this. Five channel sound, while not ideal, moves us a long ways to that concert hall experience (I was listening to E Power Biggs playing Bach in five channels last night, and even as background music it was much more "real"). Certain symphonic works, and even solo piano (Pollini's Chopin Polonaises on DG) when recorded properly transport you into a "you are there" listening environment, and the sound is just much more natural. Small groups recorded properly achieve a "they are here" dimensionality (in part due to ambience) that can be equally enthralling. At the recent AES, a perfect example was offered by Neumann, who commissioned a recording (done by Mike Pappas) of the Basie Big Band recorded live at the University of Minnesota. The recording equipment was a Sony 48 channel DSD workstation with Cardas mike cables. It was reproduced at AES from the DSD machine itself though Avalon monitors (and a custom-built subwoofer) and BAT amplifiers, again all Cardas. The sound was absolutely spectacular. I have heard this band live, and it was like them playing for you twenty feed away (which is about where I sat when I heard them live). No fancy surround gimmicks, just a good hall and a great band. Incidentally, Mike said they measured the sound pressure at the front of the band at 140db. There was no compression used. I'm hoping they get this one out as an SACD demo. The demo, btw, also demonstrated one of the drawbacks of surround sound...they could only seat 9 at a time in the room (about 20 x 15' I would guess) and of these only the first six (3 x 3 seating) were really good. The sweet spot is pretty small relative to all the real estate required for speakers. But back to Bruce's point, anybody holding out that two-channel is somehow more "natural" is simply rationalizing. Multichannel is simply more effective at reproducing music in a home listening environment. |
#3
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Hi-fi, High-end and Multi-channel reproduction
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#4
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Hi-fi, High-end and Multi-channel reproduction
I have a long-standing interest. I've been playing with multichannel
sound for decades, ever since Hafler first proposed his version. The first time I really heard what ambience can do was when Yamaha produced a "Digital Sound Processor" ,which allowed a choice of various digitally recreated ambiences: several concert halls, cinemas etc. Playing with it I realised that the main problem of many unlistenable recordings was not with faulty microphoning, distortion, peaks and dips in frequency range and so on but primarily with the place where they were recorded. This I suspect accounts for instance for some of the more horrid DG. recordings of Berliner Philharmoniker. And a lot of it could be corrected by adding better ambience. I eventually replaced the Yamaha with JVC DSP 1000 that had some areas of superiority -to my ears- mainly because it does not add its own sound.. It has the choice of 20 different concert halls etc, controls for the listening room size and reverberation, controls for the surround's early and late reverberations, (amount of and duration separately), duration of echo, high frequency stepped cut-off. A long learning curve and the danger of exceess fiddling interfering with musical experience always present) Lately it required a repair when I found out that no more similar units are being made by anyone. Lexicon has some features but not the variety of choice and controls. I have no personal experience with 5.1 sound but in principle it is limited compared to the six speaker surround of JVC. I use the Lexicon speaker setup- the two side speakers right by the sides of my listening seat rather than further up front. If used discreetly they (to me) merge perfectly At present I find symphonic, organ and pop music infinitely pleasanter to listen with surround. So do my male friends. In fact I get panicky when I think that my Yamaha DSP could one day expire irreparabely. Many solo piano and voice recordings can also stand some fiddling with surround. But a note of caution. A frequent visitor, a woman professional pianist dislikes any surround. My wife too protests against any slight indiscretio in its use. Women DO hear things that men miss. How many women hi-fi fans does anyone know? Perhaps they know better the imitation from the real than we do and do not value the attempts at closing the gap. Ludovic Mirabel "Harry Lavo" wrote in message ... "Bruce Abrams" wrote in message ... As a choral singer, I regularly have the opportunity to hear what is frequently referred to as the "absolute sound", namely unamplified music in a concert hall. As regards this reference, we audiophiles frequently question whether the purpose of a reproduction system is to recreate the original musical experience in the listening room, or whether it is to reproduce what the recording engineer heard in the control room. Recently during a rehearsal at Weil Recital Hall at Carnegie while waiting to get on stage, I was sitting in the third row of the mostly empty hall listening to a sonata for piano and cello and trying to figure out (seemingly for the zillionth time) what it was that allows the ear to so clearly distinguish even the finest quality reproduced music from the real thing. While the obvious factors such as tonal balance and dynamic range certainly contribute, I began to reconsider (again, for the zillionth time) the role that ambient sound plays. As I listened, it ocurred to me that the percentage of reflected sound to direct was probably much greater than I had previously thought (bearing in mind that while I was in row 3, the hall was mostly empty) and that the quality and quantity of reflected sound probably has as much to do with the subjective impression of "live or memorex" as does the traditionally thought of factors of tonal balance and dynamic range. Back to the original question. I have always been of the opinion that an accurate replay of the control room is all that could be hoped for, and that assuming the engineer did his job properly, a reasonable facsimile of the original event could be had. (The thinking was based in part on the concept that no listening room could be made to acoustically duplicate a concert or recording venue. This also happens to be the thinking that led to binaural recording & playback techniques.) Which brings us to the possibility that discreet multi-channel playback should be far more capable of reproducing the original acoustic space than stereo ever could hope to. This is so obvious and self-evident that I have difficulty understanding why the audiophile community continues to disparage multi-channel systems as being good for movies only. That stereo is physically incapable of placing sound behind (and to the sides of, etc.) the listener is obvious. That to accurately replicate an acoustic event requires sounds (a potentiallysignificant portion of the total sound as previously discussed) to be located behind the listener is equally obvious. The simple fact is that a concert cannot be accurately reproduced with sounds emanating only from in front of the listener. It's just not what we ever hear in the original venue. When viewed from this standpoint, even if DVD-A and SACD provide no more "resolution" in two channels than standard red-book CDs, the potential for a more accurate reproduction of the original musical event via a multi-channel experience should have all audiophiles jumping at those formats. Rather than quibbling over interconnects and speaker cables with all their limited (if at all existing) possibilities for improvement, I suggest that a far more meaningful upgrade would be the addition of 2 or 3 channels to existing systems. Save for speaker upgrades, we really have maxed out the capabilities of the stereo format. It is only through multi-channel playback that we can hope to approach a true recreation of the "absolute sound." Bruce Bruce, I agree with you completely on this. Five channel sound, while not ideal, moves us a long ways to that concert hall experience (I was listening to E Power Biggs playing Bach in five channels last night, and even as background music it was much more "real"). Certain symphonic works, and even solo piano (Pollini's Chopin Polonaises on DG) when recorded properly transport you into a "you are there" listening environment, and the sound is just much more natural. Small groups recorded properly achieve a "they are here" dimensionality (in part due to ambience) that can be equally enthralling. At the recent AES, a perfect example was offered by Neumann, who commissioned a recording (done by Mike Pappas) of the Basie Big Band recorded live at the University of Minnesota. The recording equipment was a Sony 48 channel DSD workstation with Cardas mike cables. It was reproduced at AES from the DSD machine itself though Avalon monitors (and a custom-built subwoofer) and BAT amplifiers, again all Cardas. The sound was absolutely spectacular. I have heard this band live, and it was like them playing for you twenty feed away (which is about where I sat when I heard them live). No fancy surround gimmicks, just a good hall and a great band. Incidentally, Mike said they measured the sound pressure at the front of the band at 140db. There was no compression used. I'm hoping they get this one out as an SACD demo. The demo, btw, also demonstrated one of the drawbacks of surround sound...they could only seat 9 at a time in the room (about 20 x 15' I would guess) and of these only the first six (3 x 3 seating) were really good. The sweet spot is pretty small relative to all the real estate required for speakers. But back to Bruce's point, anybody holding out that two-channel is somehow more "natural" is simply rationalizing. Multichannel is simply more effective at reproducing music in a home listening environment. |
#5
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Hi-fi, High-end and Multi-channel reproduction
I am curious as to how many ears you used when making this
"observation" and how they were arranged in relation to your head. Stereo pictures can create incredibly deep and realistic spatial detail as can stereo recordings. I would completely agree in principal with you that, equipment quality aside, technique is everything. We have had guests at our home watching movies and on several occasions have witnessed them look around the room for the other speakers and even behind them towards the street to see if someone was approaching from outside as the depth of the sound was so real as to be enveloping. We have only two speakers in the room. - Bill www.uptownaudio.com Roanoke VA (540) 343-1250 "Bruce Abrams" wrote in message ... As a choral singer, I regularly have the opportunity to hear what is frequently referred to as the "absolute sound", namely unamplified music in a concert hall. As regards this reference, we audiophiles frequently question whether the purpose of a reproduction system is to recreate the original musical experience in the listening room, or whether it is to reproduce what the recording engineer heard in the control room. Recently during a rehearsal at Weil Recital Hall at Carnegie while waiting to get on stage, I was sitting in the third row of the mostly empty hall listening to a sonata for piano and cello and trying to figure out (seemingly for the zillionth time) what it was that allows the ear to so clearly distinguish even the finest quality reproduced music from the real thing. While the obvious factors such as tonal balance and dynamic range certainly contribute, I began to reconsider (again, for the zillionth time) the role that ambient sound plays. As I listened, it ocurred to me that the percentage of reflected sound to direct was probably much greater than I had previously thought (bearing in mind that while I was in row 3, the hall was mostly empty) and that the quality and quantity of reflected sound probably has as much to do with the subjective impression of "live or memorex" as does the traditionally thought of factors of tonal balance and dynamic range. Back to the original question. I have always been of the opinion that an accurate replay of the control room is all that could be hoped for, and that assuming the engineer did his job properly, a reasonable facsimile of the original event could be had. (The thinking was based in part on the concept that no listening room could be made to acoustically duplicate a concert or recording venue. This also happens to be the thinking that led to binaural recording & playback techniques.) Which brings us to the possibility that discreet multi-channel playback should be far more capable of reproducing the original acoustic space than stereo ever could hope to. This is so obvious and self-evident that I have difficulty understanding why the audiophile community continues to disparage multi-channel systems as being good for movies only. That stereo is physically incapable of placing sound behind (and to the sides of, etc.) the listener is obvious. That to accurately replicate an acoustic event requires sounds (a potentiallysignificant portion of the total sound as previously discussed) to be located behind the listener is equally obvious. The simple fact is that a concert cannot be accurately reproduced with sounds emanating only from in front of the listener. It's just not what we ever hear in the original venue. When viewed from this standpoint, even if DVD-A and SACD provide no more "resolution" in two channels than standard red-book CDs, the potential for a more accurate reproduction of the original musical event via a multi-channel experience should have all audiophiles jumping at those formats. Rather than quibbling over interconnects and speaker cables with all their limited (if at all existing) possibilities for improvement, I suggest that a far more meaningful upgrade would be the addition of 2 or 3 channels to existing systems. Save for speaker upgrades, we really have maxed out the capabilities of the stereo format. It is only through multi-channel playback that we can hope to approach a true recreation of the "absolute sound." Bruce |
#6
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Hi-fi, High-end and Multi-channel reproduction
On 21 Oct 2003 01:48:09 GMT, "Uptown Audio"
wrote: I am curious as to how many ears you used when making this "observation" and how they were arranged in relation to your head. Stereo pictures can create incredibly deep and realistic spatial detail as can stereo recordings. I would completely agree in principal with you that, equipment quality aside, technique is everything. We have had guests at our home watching movies and on several occasions have witnessed them look around the room for the other speakers and even behind them towards the street to see if someone was approaching from outside as the depth of the sound was so real as to be enveloping. We have only two speakers in the room. While I have no doubt that inexperienced listeners can think that they are hearing sounds from behind them, there is no way that a 2 channel source on a 2 channel system can reproduce real sounds from any direction than the front. What comes from the rear and sides is the sound of your room, not the original event. That may be enough for you. Kal |
#7
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Hi-fi, High-end and Multi-channel reproduction
"Uptown Audio" wrote in message
... I am curious as to how many ears you used when making this "observation" and how they were arranged in relation to your head. Stereo pictures can create incredibly deep and realistic spatial detail as can stereo recordings. I would completely agree in principal with you that, equipment quality aside, technique is everything. We have had guests at our home watching movies and on several occasions have witnessed them look around the room for the other speakers and even behind them towards the street to see if someone was approaching from outside as the depth of the sound was so real as to be enveloping. We have only two speakers in the room. - Bill www.uptownaudio.com Roanoke VA (540) 343-1250 Last I checked, I have the same two ears that all healthy adults hopefully have. Being able to create an illusion of soundstage width and depth (I'll leave height alone for this discussion) is something we have all experienced in a stereo environment. The psychoacoustic mechanisms that allow such an illusion are well known and various tricks such as Q-sound have been employed to reasonably locate sounds laterally. Having said that, stereo is physically incapable of reproducing the reflected sound that envelopes one in a performance hall. You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. In order to surround the listener with reflected sound, you must have either more than two channels, or be listening to a closely miked recording in the original acoustic space. It just occured to me that an old KLH (I think it was KLH, but perhaps AR or Advent) experiment in the late '60s further bears out this point. The experiment was to place a small acoustic group (I can't remember the makeup of the group) on the stage of a hall alongside a pair of speakers. The audience was blindfolded and asked to pick whether they were hearing the music live or played back through the speakers, and were frequently unable to correctly choose. KLH used this a proof of the realism and naturalness of their speakers. Given that speakers of that era were hardly accurate, I suspect that something else was at play, namely the reflected sound of the hall. In this test, both the live music and the reproduced music were subject to the same acoustic properties of the hall. Reflections, reverb and decay would all have been identical regardless of whether the sound was live or reproduced (saving any discrepancies due to the radiation pattern of the speakers.) The effect of the acoustic space simply swamped any inaccuracies in the speakers thus creating the impression that it was the speakers that were responsible for the quality of playback. "Bruce Abrams" wrote in message ... As a choral singer, I regularly have the opportunity to hear what is frequently referred to as the "absolute sound", namely unamplified music in a concert hall. As regards this reference, we audiophiles frequently question whether the purpose of a reproduction system is to recreate the original musical experience in the listening room, or whether it is to reproduce what the recording engineer heard in the control room. Recently during a rehearsal at Weil Recital Hall at Carnegie while waiting to get on stage, I was sitting in the third row of the mostly empty hall listening to a sonata for piano and cello and trying to figure out (seemingly for the zillionth time) what it was that allows the ear to so clearly distinguish even the finest quality reproduced music from the real thing. While the obvious factors such as tonal balance and dynamic range certainly contribute, I began to reconsider (again, for the zillionth time) the role that ambient sound plays. As I listened, it ocurred to me that the percentage of reflected sound to direct was probably much greater than I had previously thought (bearing in mind that while I was in row 3, the hall was mostly empty) and that the quality and quantity of reflected sound probably has as much to do with the subjective impression of "live or memorex" as does the traditionally thought of factors of tonal balance and dynamic range. Back to the original question. I have always been of the opinion that an accurate replay of the control room is all that could be hoped for, and that assuming the engineer did his job properly, a reasonable facsimile of the original event could be had. (The thinking was based in part on the concept that no listening room could be made to acoustically duplicate a concert or recording venue. This also happens to be the thinking that led to binaural recording & playback techniques.) Which brings us to the possibility that discreet multi-channel playback should be far more capable of reproducing the original acoustic space than stereo ever could hope to. This is so obvious and self-evident that I have difficulty understanding why the audiophile community continues to disparage multi-channel systems as being good for movies only. That stereo is physically incapable of placing sound behind (and to the sides of, etc.) the listener is obvious. That to accurately replicate an acoustic event requires sounds (a potentiallysignificant portion of the total sound as previously discussed) to be located behind the listener is equally obvious. The simple fact is that a concert cannot be accurately reproduced with sounds emanating only from in front of the listener. It's just not what we ever hear in the original venue. When viewed from this standpoint, even if DVD-A and SACD provide no more "resolution" in two channels than standard red-book CDs, the potential for a more accurate reproduction of the original musical event via a multi-channel experience should have all audiophiles jumping at those formats. Rather than quibbling over interconnects and speaker cables with all their limited (if at all existing) possibilities for improvement, I suggest that a far more meaningful upgrade would be the addition of 2 or 3 channels to existing systems. Save for speaker upgrades, we really have maxed out the capabilities of the stereo format. It is only through multi-channel playback that we can hope to approach a true recreation of the "absolute sound." Bruce |
#8
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Hi-fi, High-end and Multi-channel reproduction
Uptown Audio wrote:
I am curious as to how many ears you used when making this "observation" and how they were arranged in relation to your head. If by this you are resurrecting the 'we only have two ears so we only need two speakers' argumetn, are you aware that the first recommendations for optimal 'stereo' reproduction, by the inventors of the format, involved using *three* front channels? -- -S. |
#9
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Hi-fi, High-end and Multi-channel reproduction
Kalman Rubinson wrote:
On 21 Oct 2003 01:48:09 GMT, "Uptown Audio" wrote: I am curious as to how many ears you used when making this "observation" and how they were arranged in relation to your head. Stereo pictures can create incredibly deep and realistic spatial detail as can stereo recordings. I would completely agree in principal with you that, equipment quality aside, technique is everything. We have had guests at our home watching movies and on several occasions have witnessed them look around the room for the other speakers and even behind them towards the street to see if someone was approaching from outside as the depth of the sound was so real as to be enveloping. We have only two speakers in the room. While I have no doubt that inexperienced listeners can think that they are hearing sounds from behind them, there is no way that a 2 channel source on a 2 channel system can reproduce real sounds from any direction than the front. What comes from the rear and sides is the sound of your room, not the original event. That may be enough for you. The closest I have come to experiencing what UA describes , is when playing some stereo Pink Floyd and Roger Waters recordings that used something called 'holophonic sound' -- and there, things did not sound like they were coming from behind me, but well off to the side. -- -S. |
#10
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Hi-fi, High-end and Multi-channel reproduction
"Bruce Abrams" wrote in message
... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. KE |
#11
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Hi-fi, High-end and Multi-channel reproduction
"All Ears" wrote in message
... "Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. That's not true. Your logic is faulty. You just effectively said that since the sky is blue, anything that is blue must be the sky. Just because the ear filters 8 kHz, sounds from the front that are cut at 8 kHz will not automatically be located to the rear. There are directional clues that will be missing. You just can't make a sound produced in front of a listener sound like it's coming from behind the listener. |
#12
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Hi-fi, High-end and Multi-channel reproduction
All Ears wrote:
"Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. KE I don't think it's that simple. Let's say you play some bass notes on speakers in front of you. There is no 8KHz in those bass notes. How can the ear interpret those as coming from the behind? |
#13
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Hi-fi, High-end and Multi-channel reproduction
Yes you can.
Don't know how it works, but it can be done. One very clear example is in the movie "Quigley down under". When Quigley arrives at his new employer's ranch he is asked to demonstrate his markmanship. In stereo (even off of VHS) if you are dead centered between your speakers, you hear very distinct echoes each time he fires his rifle, clearly from behind you. You don't get this if you move much off the centerline between the speakers. Have heard this on two high end systems, and one little all in one type home system. Also have heard other similar effects from time to time in movies. That one is just a very clear one I remember. It is well known that sound directly from the front hit both ears at once and make direction hard to determine. Front, top, behind being somewhat confused in this situation. What makes this Quigley episode so firmly from the rear I cannot say. But it does this for a few other people I know, not just for me. Dennis "Bruce Abrams" wrote in message ... "All Ears" wrote in message ... "Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. That's not true. Your logic is faulty. You just effectively said that since the sky is blue, anything that is blue must be the sky. Just because the ear filters 8 kHz, sounds from the front that are cut at 8 kHz will not automatically be located to the rear. There are directional clues that will be missing. You just can't make a sound produced in front of a listener sound like it's coming from behind the listener. |
#14
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Hi-fi, High-end and Multi-channel reproduction
Actually, your argument is faulty. What he is saying is that the brain
expects and has learned that sounds that are located to the rear have a decrease in frequency at around 8khz. Thus, when anything has such a frequency anomiliy, it creates a sensation that things appear to be heard as being behind you. That does not make them actually behind you and does not necessitate that. I think that frequency and phase relationships play a large part in sound localization and are used creatively by those who produce artificial surround programs for use with two channel systems regardless of the recording techniques. For recordings that are very well done for stereo whether intentionally, accidentally or coincidentally, the effects on the depth of soundstage are appearant. As an example of how this can work, imagine a recording of a race track, where the cars are going around you in a circle. This is a stereo recording, whre the microphones are static as you are in your listening position and the cars race in front, to your left, in behind, and to your right before finally returning to the forward position. The sound that is being recorded is the direct, in-phase sound of the cars intially, then level rduced to your right, then out-of-phase and level reduced or some frequencies thereof as the sound being recorded when they are behind you is largely of the echo from the objects in front of you like the wall and less of the actual cars, then the sound becomes more normalized in the right side until they appear in front of you once again. You can do this with six mic locations and six speaker locations as well; it will just cost you three times the amount. The trouble with recordings is that most are not done in this manner and are subsequently mixed to further reduce the effect of the live experience. Those that are well-done will reveal such spacial cues and when played back on a system with sufficient resolving capabilities will reveal them there as well. So it is not really the speakers that need to be behind you, but the brain that needs to be fed the proper signals to generate the feeling as if the events were actually happening behind you, as in real life. -Bill www.uptownaudio.com Roanoke VA (540) 343-1250 "Bruce Abrams" wrote in message ... "All Ears" wrote in message ... "Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. That's not true. Your logic is faulty. You just effectively said that since the sky is blue, anything that is blue must be the sky. Just because the ear filters 8 kHz, sounds from the front that are cut at 8 kHz will not automatically be located to the rear. There are directional clues that will be missing. You just can't make a sound produced in front of a listener sound like it's coming from behind the listener. |
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Some years back while living in a big ranch style house in San Diego I
was fortunate enough to have a largish rectangular living room (not by todays standards though). Equipment was simple enough, Polk RTA-12C's hooked to a Kenwood amp and preamp and a Fisher CD player (which I truly loved and still can't find a cd player to this day that is able to create such a warm and smooth sound as that cheap $149, 1986 cd player did). On a live recording of Def Leopard on CD, one of the tracks featured a guitar solo. The sound of that guitar emanated from behind and above me so that it was coming from where the wall met the ceiling. I enjoyed having people over and popping that CD in, as everyone would sit up, turn around and look for a speaker behind them. It was startling. You could pinpoint the spot it came from but, it was only that portion of the song featuring the guitar solo. No other portion of that song, or any other song on that CD or any other CD or vinyl record could duplicate that experience. It was really amazing. On my present system I get thrown for a loop as it seems so real when sounds come from other than the speakers when the stereo is playing the soundtrack/dialog during a video and I'm only using 2-channel. Room interface? Yes. Life-like imaging? Yes. Room interface the reason for the life-like imaging? Probably. John |
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It can actually be experienced in rather "dead" rooms with good
recordings on good equipment. My room does not really fit the "dead" description, but it is neutral having plaster walls and wall-to-wall carpet plus a very cushy couch and a lot of coverings and furnishings to break-up any reflections. I believe that phase relationships in a recording contain much of this spatial information. I am sure that you have a few miles on your ears as well, but I am comfortable with my own experiences and do not feel that I need you to justify or approve of them to make them more real. We have both very high resolution stereo and surround systems to listen to and I hear distinctly different presentaions of sound field depth from each. That may or may not be enough for you. - Bill www.uptownaudio.com Roanoke VA (540) 343-1250 "Kalman Rubinson" wrote in message ... On 21 Oct 2003 01:48:09 GMT, "Uptown Audio" wrote: I am curious as to how many ears you used when making this "observation" and how they were arranged in relation to your head. Stereo pictures can create incredibly deep and realistic spatial detail as can stereo recordings. I would completely agree in principal with you that, equipment quality aside, technique is everything. We have had guests at our home watching movies and on several occasions have witnessed them look around the room for the other speakers and even behind them towards the street to see if someone was approaching from outside as the depth of the sound was so real as to be enveloping. We have only two speakers in the room. While I have no doubt that inexperienced listeners can think that they are hearing sounds from behind them, there is no way that a 2 channel source on a 2 channel system can reproduce real sounds from any direction than the front. What comes from the rear and sides is the sound of your room, not the original event. That may be enough for you. Kal |
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I have never been aware of that, rather of the facts. Please visit:
http://history.acusd.edu/gen/recording/stereo.html http://www.headwize.com/articles/kvenn_art.htm for just a couple of references to what has actually taken place. Three channel recordings were an idea to create a greater dynamic response and to fill-in any space that was not complete as a result of recording technicalities or listening positions. Even still, there was only one "optimum" position for listening as is still the case for any playback system independent of the head. When coupled with video, even the head-mounted systems must remain in proper orientation until we develop eyes eleswhere... - Bill www.uptownaudio.com Roanoke VA (540) 343-1250 "Steven Sullivan" wrote in message . net... Uptown Audio wrote: I am curious as to how many ears you used when making this "observation" and how they were arranged in relation to your head. If by this you are resurrecting the 'we only have two ears so we only need two speakers' argumetn, are you aware that the first recommendations for optimal 'stereo' reproduction, by the inventors of the format, involved using *three* front channels? -- -S. |
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On Wed, 22 Oct 2003 00:32:24 GMT, "Uptown Audio"
wrote: Actually, your argument is faulty. What he is saying is that the brain expects and has learned that sounds that are located to the rear have a decrease in frequency at around 8khz. Thus, when anything has such a frequency anomiliy, it creates a sensation that things appear to be heard as being behind you. As long as you have other cues to accompany that one. In the interesting and detailed example that you give, phase and, most important, expectation play important roles. Without the change of direction and the change in phase and the experience of oval tracks, the 8KHz cut is insufficient. That said, the frequency cut cannot, by itself, cause one to hear the sound of a musical instrument or voice behind you. And further, while one can manipulate a number of parameters to simulate rear/surround effects, the fact remains that normal, well-produced stereo recordings do not convey any rear/surround information that is not mixed irretrievably with the front signals. Just listen to all the sound decay forward as an example. Kal |
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Uptown Audio wrote:
I have never been aware of that, rather of the facts. Please visit: http://history.acusd.edu/gen/recording/stereo.html http://www.headwize.com/articles/kvenn_art.htm for just a couple of references to what has actually taken place. Three channel recordings were an idea to create a greater dynamic response and to fill-in any space that was not complete as a result of recording technicalities or listening positions. Yup. Like I said, three channels were considered ideal. see also: http://www.dynaudioacoustics.com/Fil..._Sourround.pdf from which I extract this quote (from p 4 of 16): "While it was the general consensus that three channels was the ideal number for optimum music playback, two-channel stereo became the standard mostly for reasons of cost, convenience and commercial practicality in connection with the introduction of the LP and FM Stereo." Even still, there was only one "optimum" position for listening as is still the case for any playback system independent of the head. When coupled with video, even the head-mounted systems must remain in proper orientation until we develop eyes eleswhere... And this makes stereo preferable to multichannel how? 'Audiophiles' surely are used to the idea of there being one *best* sweet spot. |
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On 21 Oct 2003 20:18:37 GMT, Bruce Abrams
wrote: "All Ears" wrote in message ... "Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. That's not true. Your logic is faulty. You just effectively said that since the sky is blue, anything that is blue must be the sky. Just because the ear filters 8 kHz, sounds from the front that are cut at 8 kHz will not automatically be located to the rear. There are directional clues that will be missing. You just can't make a sound produced in front of a listener sound like it's coming from behind the listener. That's not true. Your logic is faulty. There are no 'directional clues' in a direct front to direct rear traverse that don't involve manipulation of the HRTF. Indeed, aside from transients, we generally have great difficulty in distinguishing a sound directly in front from one directly behind, *unless* it has significant HF content. Those designing warning sirens for emergency service vehicles are well aware of this - as is anyone who has ever tried to find their mobile phone when it rings! -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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On 21 Oct 2003 19:33:00 GMT, "All Ears" wrote:
"Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. Indeed, I notice an *extremely* persuasive overhead front to back movement of the sound image of USS Enterprise in Star Trek VI, which I expect is a combination of phase and frequency manipulation. I use only two speakers for TV sound. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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On 21 Oct 2003 22:48:38 GMT, chung wrote:
All Ears wrote: "Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. KE I don't think it's that simple. Let's say you play some bass notes on speakers in front of you. There is no 8KHz in those bass notes. How can the ear interpret those as coming from the behind? How can it interpret them as coming from *any* location? Ever tried to decide which phone in a modern office is ringing? -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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And further, while one can manipulate a number of parameters to
simulate rear/surround effects, the fact remains that normal, well-produced stereo recordings do not convey any rear/surround information that is not mixed irretrievably with the front signals. Just listen to all the sound decay forward as an example. And why would you expect the sound decay NOT to sound like it was coming from forward? I've never heard an unamplified live concert where anything sounded like it was coming from anywhere other than right where the musicians are. Not even in a giant and very "live" church, where the room ambiance was almost louder than the musicians - it still sounded like everything was coming from right where they were playing. So I don't understand why people would want systems where the room ambiance comes from somewhere other than the front. To me, if it ever sounded like it wasn't at the front, I would consider it very unrealistic. Do other people hear reverberations sounding as though they're coming from the walls? If so, that would explain the interest in multi-channel. To me, it just seems like inviting trouble for no good reason. Bob |
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Stewart Pinkerton wrote:
On 21 Oct 2003 22:48:38 GMT, chung wrote: All Ears wrote: "Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. KE I don't think it's that simple. Let's say you play some bass notes on speakers in front of you. There is no 8KHz in those bass notes. How can the ear interpret those as coming from the behind? How can it interpret them as coming from *any* location? Ever tried to decide which phone in a modern office is ringing? OK Stewart, I'll bite. How does one know if sound is from the back? I have always thought that it is the difference in amplitude and phase of the sounds arriving at the left and right ears that provide location information. But obviously, if a sound is coming from behind you in the middle, there may not be any difference in what each ear perceives. On the other hand, I don't think it's as simple as a notch filter around 8 KHz. A telephone ringtone does not have much 8KHz component, yet clearly I can tell if a phone is ringing behind me. When one of the many phones rings, I think most of us will turn our heads to find a spot where the sound is somewhat front-center of us, and then focus on the ringing source. Well, most of the time at least. What if a 1KHz tone is played. Can one tell if the tone comes from the back or front without turning one's head? |
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wrote in message ...
And further, while one can manipulate a number of parameters to simulate rear/surround effects, the fact remains that normal, well-produced stereo recordings do not convey any rear/surround information that is not mixed irretrievably with the front signals. Just listen to all the sound decay forward as an example. And why would you expect the sound decay NOT to sound like it was coming from forward? Because in a concert hall, sounds don't emanate solely from the stage. Listen to the end of a tutti orchestral passage and then try to locate the decay. You can't because it quite literally comes from all directions. You might not perceive it as coming from anywhere, in fact, because it just seems to be part of the room. I've never heard an unamplified live concert where anything sounded like it was coming from anywhere other than right where the musicians are. Not even in a giant and very "live" church, where the room ambiance was almost louder than the musicians - it still sounded like everything was coming from right where they were playing. So I don't understand why people would want systems where the room ambiance comes from somewhere other than the front. To me, if it ever sounded like it wasn't at the front, I would consider it very unrealistic. Do other people hear reverberations sounding as though they're coming from the walls? Absolutely. Not only from the walls, but from the ceiling, floor, in fact from all surfaces in the hall. |
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On Wed, 22 Oct 2003 18:24:15 GMT, chung wrote:
Stewart Pinkerton wrote: On 21 Oct 2003 22:48:38 GMT, chung wrote: All Ears wrote: "Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. KE I don't think it's that simple. Let's say you play some bass notes on speakers in front of you. There is no 8KHz in those bass notes. How can the ear interpret those as coming from the behind? How can it interpret them as coming from *any* location? Ever tried to decide which phone in a modern office is ringing? OK Stewart, I'll bite. How does one know if sound is from the back? One doesn't, unless one turns one's head. We often have difficulty in locating sound directly behind us - until we turn our heads slightly. I have always thought that it is the difference in amplitude and phase of the sounds arriving at the left and right ears that provide location information. But obviously, if a sound is coming from behind you in the middle, there may not be any difference in what each ear perceives. Quite so. On the other hand, I don't think it's as simple as a notch filter around 8 KHz. Not notch, low pass. A telephone ringtone does not have much 8KHz component, yet clearly I can tell if a phone is ringing behind me. A mechanical bell tone most certainly does have significant HF content, and such a ringtone is *much* easier to locate than modern tone generator 'rings'. Do you really claim to be able to locate an electronic ring, such as most mobile phones or office phones? When one of the many phones rings, I think most of us will turn our heads to find a spot where the sound is somewhat front-center of us, and then focus on the ringing source. Well, most of the time at least. What if a 1KHz tone is played. Can one tell if the tone comes from the back or front without turning one's head? There is absolutely no way to locate a steady sinusoid, except by walking around to follow amplitude variation. Try it sometime. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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I have experienced a good example of what Stewart is
talking about here. Where I work, there was a large all metal building about 35 x60 feet with 25 foot sloping ceilings. It held some electrical and electronic equipment all around the periphery. There were about 3 dozen microprocessor monitor panels with each piece of equipment being monitored. When certain conditions occurred, an alarm would sound from that panel. It sounded like maybe 1khz, and a sine wave or close to it. Well if an alarm sounded it was pretty much impossible in this highly reflective open space to figure out where it was coming from. The alarm was the tone only. So you had to start at one end, pull up the alarm display screen, and work your way through it until you came across the right one. A terrible design. A light should also have blinked on the panel or something. This is also highly disconcerting to move where it seems to be coming from only to have it sound like some place else when you get there. You simply couldn't tract it down via the sound. Dennis "Stewart Pinkerton" wrote in message ... On Wed, 22 Oct 2003 18:24:15 GMT, chung wrote: Stewart Pinkerton wrote: On 21 Oct 2003 22:48:38 GMT, chung wrote: All Ears wrote: "Bruce Abrams" wrote in message ... snip You just can't reproduce sounds from behind you with speakers in front of you. It's impossible. This is not entirely true, actually the ears works as a filter, so that sounds comming from behind will have a dramatic drop in the 8 kHz area. This means that if you cut the 8kHz area from a sound image, it will appear as the sound is comming from behind. KE I don't think it's that simple. Let's say you play some bass notes on speakers in front of you. There is no 8KHz in those bass notes. How can the ear interpret those as coming from the behind? How can it interpret them as coming from *any* location? Ever tried to decide which phone in a modern office is ringing? OK Stewart, I'll bite. How does one know if sound is from the back? One doesn't, unless one turns one's head. We often have difficulty in locating sound directly behind us - until we turn our heads slightly. I have always thought that it is the difference in amplitude and phase of the sounds arriving at the left and right ears that provide location information. But obviously, if a sound is coming from behind you in the middle, there may not be any difference in what each ear perceives. Quite so. On the other hand, I don't think it's as simple as a notch filter around 8 KHz. Not notch, low pass. A telephone ringtone does not have much 8KHz component, yet clearly I can tell if a phone is ringing behind me. A mechanical bell tone most certainly does have significant HF content, and such a ringtone is *much* easier to locate than modern tone generator 'rings'. Do you really claim to be able to locate an electronic ring, such as most mobile phones or office phones? When one of the many phones rings, I think most of us will turn our heads to find a spot where the sound is somewhat front-center of us, and then focus on the ringing source. Well, most of the time at least. What if a 1KHz tone is played. Can one tell if the tone comes from the back or front without turning one's head? There is absolutely no way to locate a steady sinusoid, except by walking around to follow amplitude variation. Try it sometime. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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"Stewart Pinkerton" wrote in message
... *snip* OK Stewart, I'll bite. How does one know if sound is from the back? One doesn't, unless one turns one's head. We often have difficulty in locating sound directly behind us - until we turn our heads slightly. This comment actually helps makes the case for multi-channel. Unless you sit at a live event wearing a head clamp, your ears' positions relative to both direct and indirect sound is constantly changing. Moving around, changing your position, looking around the hall, etc. The reality of the source of ambient sound is thus the reality. You hear the ambience from all directions, because it really is coming from all directions, and while your head position changes, the source of the sound is constant and thus you have audible confirmation that you are moving your head. (This is one of the reasons that headphone listening, even with an AirHead processor, is somewhat unrealistic. While your head moves around, you have no audible sense that your are.) The only way of coming close to this in a listening room is with multiple channels. The only question, is how many channels are required and how should they be arrayed. Thinking out loud, here's one possibility. It's been well established for nearly 50 years, that two channels is sufficient to provide the illusion of a continuous lateral soundstage. This is the basis of stereo. If two channels can accomplish this laterally at the front, it seems reasonable that two channels should be able to create the same illusion for both the rear and sides of an enveloping sound field. In other words, two rear channels should be able to do no worse of a job reproducing the rear ambience of a hall, than the front two channels do of producing the front. Likewise with the side reflections. In such a scenario (ie 4 discreetly recorded & played back channels), the front speakers work together for the front image, the rear speakers provide the rear, the left speakers (front & rear) provide the left side, and the right speakers (front & rear) provide the right side. The problem with such a setup would be a relatively limited sweet spot, as you would be limited longitudinally (for the front-rear speaker combinations) in much the same way as stereo is limited laterally. One way to minimize the sweet spot problem might be the addition of one extra side channel on each side. This would have a similar effect as the addition of a third channel to stereo. (Never having experienced discreet 3 channel playback, I don't know how the sweet spot is compared with 2 channel, but I suspect it is larger.) So, while 4 channels would seem to provide adequate coverage of the entire horizontal sound field albeit with a rather limited sweet spot, perhaps the addition of 4 center channels (front, sides & rear) minimizes this limitation. Any comments? Just thinking out loud. |
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Recall JJ or someone saying research into how many channels
was enough had been done. And the minimum was 7 equally spaced. I guess 8 would give you the result you need. Obviously the marketing of 5.1 is simply that more is better. If it were done in relation to what could give you truly continuous and lifelike surround sound, then they would be pushing 7 or 8 channels. Which they of course will once 5 is firmly established. Anybody think 16 might be better still? Dennis "Bruce Abrams" wrote in message news:eHimb.20136$e01.38611@attbi_s02... "Stewart Pinkerton" wrote in message ... *snip* OK Stewart, I'll bite. How does one know if sound is from the back? One doesn't, unless one turns one's head. We often have difficulty in locating sound directly behind us - until we turn our heads slightly. This comment actually helps makes the case for multi-channel. Unless you sit at a live event wearing a head clamp, your ears' positions relative to both direct and indirect sound is constantly changing. Moving around, changing your position, looking around the hall, etc. The reality of the source of ambient sound is thus the reality. You hear the ambience from all directions, because it really is coming from all directions, and while your head position changes, the source of the sound is constant and thus you have audible confirmation that you are moving your head. (This is one of the reasons that headphone listening, even with an AirHead processor, is somewhat unrealistic. While your head moves around, you have no audible sense that your are.) The only way of coming close to this in a listening room is with multiple channels. The only question, is how many channels are required and how should they be arrayed. Thinking out loud, here's one possibility. It's been well established for nearly 50 years, that two channels is sufficient to provide the illusion of a continuous lateral soundstage. This is the basis of stereo. If two channels can accomplish this laterally at the front, it seems reasonable that two channels should be able to create the same illusion for both the rear and sides of an enveloping sound field. In other words, two rear channels should be able to do no worse of a job reproducing the rear ambience of a hall, than the front two channels do of producing the front. Likewise with the side reflections. In such a scenario (ie 4 discreetly recorded & played back channels), the front speakers work together for the front image, the rear speakers provide the rear, the left speakers (front & rear) provide the left side, and the right speakers (front & rear) provide the right side. The problem with such a setup would be a relatively limited sweet spot, as you would be limited longitudinally (for the front-rear speaker combinations) in much the same way as stereo is limited laterally. One way to minimize the sweet spot problem might be the addition of one extra side channel on each side. This would have a similar effect as the addition of a third channel to stereo. (Never having experienced discreet 3 channel playback, I don't know how the sweet spot is compared with 2 channel, but I suspect it is larger.) So, while 4 channels would seem to provide adequate coverage of the entire horizontal sound field albeit with a rather limited sweet spot, perhaps the addition of 4 center channels (front, sides & rear) minimizes this limitation. Any comments? Just thinking out loud. |
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Dennis Moore wrote:
Recall JJ or someone saying research into how many channels was enough had been done. And the minimum was 7 equally spaced. I guess 8 would give you the result you need. Obviously the marketing of 5.1 is simply that more is better. If it were done in relation to what could give you truly continuous and lifelike surround sound, then they would be pushing 7 or 8 channels. 6.1 and 7.1 are indeed becoming increasingly available on A/C receivers. Which they of course will once 5 is firmly established. Anybody think 16 might be better still? I believe 10 (or 12?) channel setups to have their advocates. -- -S. |
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"Uptown Audio" wrote:
I am curious as to how many ears you used when making this "observation" and how they were arranged in relation to your head. Stereo pictures can create incredibly deep and realistic spatial detail as can stereo recordings. I would completely agree in principal with you that, equipment quality aside, technique is everything. We have had guests at our home watching movies and on several occasions have witnessed them look around the room for the other speakers and even behind them towards the street to see if someone was approaching from outside as the depth of the sound was so real as to be enveloping. We have only two speakers in the room. - Bill www.uptownaudio.com Roanoke VA (540) 343-1250 I suspect many, if not most of us have given this at least some thought. As to your question about how many ears one has to hear sound, a better question might be how many channels of sound does it take to re-create a TRUE live sounding recording. I.e., our ears can hear sound coming from all around us but a two speaker stereo system, while VERY good, is unable to do this. I have experimented with stereo (3D) photos using a process called anaglyph. This, much like stereo audio, combines two pictures taken from a slightly different angle and you use a pair of Red/Blue or Red/Green 3-D glasses to combine these pictures. The result is that you do get a somewhat more realistic photo because of the added depth and it increases the "fun" factor. However, no one would be fooled into thinking this pictures were real. A hologram would provide a MUCH more realistic image but requires more than a stereo pair. This is much the same in audio. We only have two ears and two eyes but we are able to perceive MUCH more than stereo can provide. NOTE: I am NOT knocking stereo in any way. Stereo production done well is extremely satisfying. But multi channel done well is even better. Unfortunately, many in the recording industry believe we want the instruments in musical performances spread all around us instead of using multiple channels to create a true holographic concert experience. Richard |
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On 25 Oct 2003 02:53:11 GMT, "Dennis Moore"
wrote: Recall JJ or someone saying research into how many channels was enough had been done. And the minimum was 7 equally spaced. I guess 8 would give you the result you need. One reason we need more is that we humans do not locate a phantom lateral source (created by a front and rear transducer on the same side) as well as we locate a phantom center source (created from L and R transducers). Kal |
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Hi-fi, High-end and Multi-channel reproduction
"Kalman Rubinson" wrote in message
news:YLEmb.21684$mZ5.82013@attbi_s54... On 25 Oct 2003 02:53:11 GMT, "Dennis Moore" wrote: Recall JJ or someone saying research into how many channels was enough had been done. And the minimum was 7 equally spaced. I guess 8 would give you the result you need. One reason we need more is that we humans do not locate a phantom lateral source (created by a front and rear transducer on the same side) as well as we locate a phantom center source (created from L and R transducers). Kal I would guess this is partly why the ITU standard calls for the "surround" speakers to be at 110 degrees...it puts them far enough "forward" that the early can locate the directionality to some degree, versus further "back" in the rear. However, from my experience living with it for a year now, I'd have to say that it is barely adequate, and I can see where 7.1 with "side" speakers as well as rears would be a pretty big plus. Of course, for pure ambience it probably wouldn't make a huge difference, but in a pop surround mix it certainly would. I'm not holding my breath, though, either for fitting the equipment in a non-dedicated room and getting two additional channels onto disk are both pretty big challenges. My guess is we are stuck for better or worse withy 5.1 for most purposes, including our surround music. |
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Hi-fi, High-end and Multi-channel reproduction
Giving that some thought; wouldn't it make sense then that sound
engineers seem to be lacking in the ability to create a true 3D sound reproduction in that they are using too many source mikes and not a pair (as in your ears) and letting the hall acoustic create it's own 3D effect (as in your analogy of multiple unlimited actually sources of sound)? Would you then suggest that a concert could not be fully enjoyed by a person with only two ears or that two acurate recording devices would not best mimick that experience? What I am saying is that regardless of how many points in space sound may eminate from, it is perceived by only two receptors. Thus it can stand to reason that it can be recorded in that fashion if the devices used are adequate and can recover the proper spectrum from the same directions. Playback would then require only two channels, yet would contain information received directly and by reflection and frequency/phase relation from the original hall in it's entirety. Once we get the recording done properly, playback is definately the most difficult task as it requires the power and scale to recreate the event without losing those spacial cues to it's own distortions. Speaking of stereo pictures, you should see the latest 3D film technology by Sensio for a real attention grabber. It is flat-out fun. I believe that it uses two cameras to record the scenes/movies and then it has a special digital engine that combines them at a very fast rate which is practically seamless, sort of like digital audio sampling in effect but not really in principle. I did not really have time to read-up on how it is done, but did get to see a cool demo film, which was better than any 3D video that I have seen to date. Now the ultimate 3D sound transducer must be in the form of a concave film that wraps completely around the front, side, rear and over the tops and bottom edges (like a planetarium, but with a flat roof and floor hey, walking in should not be too challenging, eh?). Full frequency from any angle and linear at all points and times. OK, that's sort of creeping me out now... - Bill www.uptownaudio.com Roanoke VA (540) 343-1250 "Richard" wrote in message ... "Uptown Audio" wrote: I am curious as to how many ears you used when making this "observation" and how they were arranged in relation to your head. Stereo pictures can create incredibly deep and realistic spatial detail as can stereo recordings. I would completely agree in principal with you that, equipment quality aside, technique is everything. We have had guests at our home watching movies and on several occasions have witnessed them look around the room for the other speakers and even behind them towards the street to see if someone was approaching from outside as the depth of the sound was so real as to be enveloping. We have only two speakers in the room. - Bill www.uptownaudio.com Roanoke VA (540) 343-1250 I suspect many, if not most of us have given this at least some thought. As to your question about how many ears one has to hear sound, a better question might be how many channels of sound does it take to re-create a TRUE live sounding recording. I.e., our ears can hear sound coming from all around us but a two speaker stereo system, while VERY good, is unable to do this. I have experimented with stereo (3D) photos using a process called anaglyph. This, much like stereo audio, combines two pictures taken from a slightly different angle and you use a pair of Red/Blue or Red/Green 3-D glasses to combine these pictures. The result is that you do get a somewhat more realistic photo because of the added depth and it increases the "fun" factor. However, no one would be fooled into thinking this pictures were real. A hologram would provide a MUCH more realistic image but requires more than a stereo pair. This is much the same in audio. We only have two ears and two eyes but we are able to perceive MUCH more than stereo can provide. NOTE: I am NOT knocking stereo in any way. Stereo production done well is extremely satisfying. But multi channel done well is even better. Unfortunately, many in the recording industry believe we want the instruments in musical performances spread all around us instead of using multiple channels to create a true holographic concert experience. Richard |
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Hi-fi, High-end and Multi-channel reproduction
On Wed, 29 Oct 2003 06:02:14 GMT, "Uptown Audio"
wrote: Giving that some thought; wouldn't it make sense then that sound engineers seem to be lacking in the ability to create a true 3D sound reproduction in that they are using too many source mikes and not a pair (as in your ears) and letting the hall acoustic create it's own 3D effect (as in your analogy of multiple unlimited actually sources of sound)? Would you then suggest that a concert could not be fully enjoyed by a person with only two ears or that two acurate recording devices would not best mimick that experience? What I am saying is that regardless of how many points in space sound may eminate from, it is perceived by only two receptors. This is an oversimplification. YOur two ears, including external, middle and internal portions, plus your brain can interpret 3D sound in the real world because they are getting 3D sound. You cannot record 3D sound (not a good term but I quote it from you) with only two receptor sets unless you add a brain (as does, to a degree, the Soundfield Mike). Give the human system 2 sources and it cannot interpret (accurately) what the 3D original was. Kal |
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Hi-fi, High-end and Multi-channel reproduction
"Kalman Rubinson" wrote in message
news:47Snb.57301$HS4.298229@attbi_s01... This is an oversimplification. YOur two ears, including external, middle and internal portions, plus your brain can interpret 3D sound in the real world because they are getting 3D sound. You cannot record 3D sound (not a good term but I quote it from you) with only two receptor sets unless you add a brain (as does, to a degree, the Soundfield Mike). Give the human system 2 sources and it cannot interpret (accurately) what the 3D original was. That's not entirely true. While the difficulties of true binaural recording are myriad, when done properly for a specific listener, the results are quite startling in their replication of the original event. Unfortunately, the difficulties render the process impractical. |