Home |
Search |
Today's Posts |
|
#1
Posted to rec.audio.high-end
|
|||
|
|||
Mind Stretchers
"Gary Eickmeier" wrote in message
... OK, I have been sufficiently worked over for now. I thank you all - or both - for some great discussion. You have read what I said, and that is all I can ask. NOW, assuming I am all washed up, that my statements that there is no stereo theory even at this late date in audio history is wrong, I sit at your feet as a student. How does stereo work? Strictly speaking Stereo over speakers doesn't work because it can't work. It's just like a car with 110% thermodynamic efficiency. It is an acceptable illusion or at least an illusion that many find acceptable. |
#2
Posted to rec.audio.high-end
|
|||
|
|||
Mind Stretchers
"Arny Krueger" wrote in message
... Strictly speaking Stereo over speakers doesn't work because it can't work. It's just like a car with 110% thermodynamic efficiency. It is an acceptable illusion or at least an illusion that many find acceptable. Hi Arn - For the record (so to speak) - when I use the term "stereo" I am using it as shorthand for any and all loudspeaker based auditory perspective systems. This would include 3 channel, DD 5.1 surround sound, or any number of speakers placed around a room to try and reconstruct a sound field that mimics the original. I realize that to some, "stereo" means strictly two channel, but that is not what I mean. But if I use "surround" or "multichannel" in all discussions, people will think I am limiting the discussion to more than two channels, which I am not. Stereo can work with two or more speakers and the general principles apply to all of these. I hope that most of you are listening in surround sound to all recordings, even two channel. If so, you are at least partially agreeing with me on the reconstruction principle. If not, I've got my work cut out for me.... Gary Eickmeier |
#3
Posted to rec.audio.high-end
|
|||
|
|||
Mind Stretchers
On Mon, 28 May 2012 11:13:04 -0700, Gary Eickmeier wrote
(in article ): "Arny Krueger" wrote in message ... Strictly speaking Stereo over speakers doesn't work because it can't work. It's just like a car with 110% thermodynamic efficiency. It is an acceptable illusion or at least an illusion that many find acceptable. Hi Arn - For the record (so to speak) - when I use the term "stereo" I am using it as shorthand for any and all loudspeaker based auditory perspective systems. This would include 3 channel, DD 5.1 surround sound, or any number of speakers placed around a room to try and reconstruct a sound field that mimics the original. I realize that to some, "stereo" means strictly two channel, but that is not what I mean. But if I use "surround" or "multichannel" in all discussions, people will think I am limiting the discussion to more than two channels, which I am not. Stereo can work with two or more speakers and the general principles apply to all of these. I hope that most of you are listening in surround sound to all recordings, even two channel. If so, you are at least partially agreeing with me on the reconstruction principle. If not, I've got my work cut out for me.... Gary Eickmeier Frankly, I find that the recording industry has a hard enough time doing two channel stereo correctly, much less four channels, or five or seven.... Now for movies where the extra channels have explosions and other sound effects pan-potted to them, it's fine, but I have yet to hear a music surround recording where I thought that the surround was any more than a gimmick. |
#4
Posted to rec.audio.high-end
|
|||
|
|||
Mind Stretchers
Gary Eickmeier wrote:
For the record (so to speak) - when I use the term "stereo" I am using it as shorthand for any and all loudspeaker based auditory perspective systems. This would include 3 channel, DD 5.1 surround sound, or any number of speakers placed around a room to try and reconstruct a sound field that mimics the original. I realize that to some, "stereo" means strictly two channel, but that is not what I mean. But if I use "surround" or "multichannel" in all discussions, people will think I am limiting the discussion to more than two channels, which I am not. Stereo can work with two or more speakers and the general principles apply to all of these. Mr. Eickmeier, you have a lonn history of taking a term, redefining it for the purposes of some agenda, without letting anyone else know about your surreptitious redefinition, and then proceeding to argue from that point. For the record, "surround sound" was NEVER designed as a means of recreating the original sound field. Things like 5.1 surround and the like were developed as effects systems used in conjunction with video and the like. James Jophnston has elsewhere described how completely innappropriate surrtound-sound systems are for recreating sound fields. Perhaps you might want to research the subject before you hold forth on it. As to the "definition" of stereo sound, you may well like to redefinf it however you like, but you should note that there's an 80 jump on your claim to the definition, and should you disagree, you might want to take it up with the kind folks at Bell Labs. I hope that most of you are listening in surround sound to all recordings, even two channel. If so, you are at least partially agreeing with me on the reconstruction principle. If not, I've got my work cut out for me.... Yes, among other things, you have a LOT of reading up to do, not the least of which is on fundamental definitions. -- +--------------------------------+ + Dick Pierce | + Professional Audio Development | +--------------------------------+ |
#5
Posted to rec.audio.high-end
|
|||
|
|||
Mind Stretchers
On Tue, 29 May 2012 03:30:00 -0700, Dick Pierce wrote
(in article ): snip As to the "definition" of stereo sound, you may well like to redefinf it however you like, but you should note that there's an 80 jump on your claim to the definition, and should you disagree, you might want to take it up with the kind folks at Bell Labs. Now here, you and I agree. Bell Labs defined stereo for the ages back in the early 1930's as I have mentioned at least once in this thread. Mr. Eickmeier's attempt to redefine it is fraught with problems, to say the least. |
#6
Posted to rec.audio.high-end
|
|||
|
|||
Mind Stretchers
"Dick Pierce" wrote in message
... Mr. Eickmeier, you have a lonn history of taking a term, redefining it for the purposes of some agenda, without letting anyone else know about your surreptitious redefinition, and then proceeding to argue from that point. Mr. Pierce, what a treat! Thank you for taking the time to share your extensive knowledge. For the record, "surround sound" was NEVER designed as a means of recreating the original sound field. Things like 5.1 surround and the like were developed as effects systems used in conjunction with video and the like. James Jophnston has elsewhere described how completely innappropriate surrtound-sound systems are for recreating sound fields. Perhaps you might want to research the subject before you hold forth on it. Hey, what a great idea! But, indeed, I have been reading voraciously about all this for over 30 years now! But I didn't stumble across a statement like that - do you have any references or quotes to help us out here?. As to the "definition" of stereo sound, you may well like to redefinf it however you like, but you should note that there's an 80 jump on your claim to the definition, and should you disagree, you might want to take it up with the kind folks at Bell Labs. Gosh, it sure seems like you know something there that I don't - but. I have quoted the research from Bell Labs in my various papers and writings. My favorite reference is William B. Snow's 1953 paper that is republished in the AES Anthology of Stereophonic Techniques. In it, he defines all of the auditory perspective systems. Yes, among other things, you have a LOT of reading up to do, not the least of which is on fundamental definitions. Thanks for the tip. So let me read to you for a minute: From R. Vermeulen's paper on Stereo Reverberation (JAES, vol. 6, no. 2, pp. 124 - 130, 1958 April): NECESSITY FOR AUGMENTED REVERBERATION It is true that by suitable positioning of the microphone we can pick up reverberation sound from the hall and reproduce the plolongation of the sound. But here again, we are apt to make the same mistake in that we reproduce only one and - of course - the only measurable characteristic of the sound field, viz, the reverberation time, but neglect its spatial distribution. The loudspeakers of a stereophonic set can never reproduce the sound field in the concert hall with any accuracy in the home; how indeed could they do so with only the data from two microphones at their disposal? Neither can they deliver to the listener's ears exact copies of the instantaneous sound pressure at the place of the microphones, if only because the listeners are free to move their heads and are sitting at different places. The loudspeakers can only produce a quite different sound field, which will nevertheless give an impression that resembles the original in certain respects. But not in all rexpects, beause they are only capable of simulating sound sources in the space between them. Thus stereophony can only widen the "hole in the wall of the concert hall" to a "large window" but it cannot give the listener the impression that he is present in the auditorium. It cannot imitate the sound reflected from all sides by the ceiling and the walls. This does not matter as long as the reproduction takes place in the concert hall itself where the ceiling and the walls are present to produce reverberated sound with the desired properties. In a living room, however, the absence of enough reverberated sound or at least its different character places the listener in the positon of an outsider." He goes on to describe how to simulate the reverberant field by means of a distribution of loudspeakers. Permit me one more quote, this time from Blauert (the well-known Spatial Hearing book, p 282) in describing the two basic approaches to transmitting a spatial impression across a distance of space and time: "In principle two approaches to solving this problem are possible. One consists of generating a sound field in the playback room that corresponds largely to that in the recording room. Such an electroacoustically generated sound field is called a 'synthetic sound field.' The second approach proceeds from the assumption that an optimal acoustical reproduction is attained if the subject's ear input signals are collected, transmitted, and reproduced. Processes employing this technique are called binaural or 'head related' since a head, usually a dummy head, is used in collecting the ear input signals." His "synthetic sound field" is a large collection of microphones leading to a similar number of speakers around the subject in an anechoic environment, in an attempt to duplicate the original field as much as possible, or necessary. Surround sound in the home theater system is a simplification of this approach, which most of us realize by common sense. You might want to do some more reading on this subject, starting with those two sources. It is possible that you could use some reinforcement in acoustics and psychoacoustics. Gary Eickmeier |
#7
Posted to rec.audio.high-end
|
|||
|
|||
Mind Stretchers
On 5/30/2012 2:41 AM, Gary Eickmeier wrote:
"Dick wrote in message ... large snip Thanks for the tip. So let me read to you for a minute: From R. Vermeulen's paper on Stereo Reverberation (JAES, vol. 6, no. 2, pp. 124 - 130, 1958 April): NECESSITY FOR AUGMENTED REVERBERATION It is true that by suitable positioning of the microphone we can pick up reverberation sound from the hall and reproduce the prolongation of the sound. my emphasis. Quite a relevant point that I've been endeavoring to have you understand. Thank you for pointing out the reference - there is no "spatial" information in the signal. Level and arrival time. That's it. But here again, we are apt to make the same mistake in that we reproduce only one and - of course - the only measurable characteristic of the sound field, viz, the reverberation time, Note - time...the *only* measurable characteristic. There is no other recording parameter to capture "spatial" information. Here's your answer to your "smartass" question. Rhetorical on your part evidently. but neglect its spatial distribution. The loudspeakers of a stereophonic set can never reproduce the sound field in the concert hall with any accuracy in the home; how indeed could they do so with only the data from two microphones at their disposal? Wow, this guy's good. You indeed can never reproduce the sound field in the venue when using only two microphones for the recording. Why? Simply because, as he states above, the spatial information is not encoded in the signal. Note, recordings using 3 mics, or any number of close-miked instruments panned into place will suffer the exact same effects. Wonder where I've heard that before... snip He goes on to describe how to simulate the reverberant field by means of a distribution of loudspeakers. And corresponding microphones. This in no wise supports your method of taking a signal devoid of non-temporal spatial information (i.e. no incident angle info) and by bouncing the entire - direct and reverberant - signal off the wall(s), thereby introducing an artificially delayed acoustic wave superimposed on the directly radiated signal (which also contains both the direct and reverberant data). While you may sense that as spaciousness, it is clearly less accurate. And as Mr. Pierce accurately observed, morphing the term "stereo" to incorporate any number of speakers in any configuration is, IMO, clearly a dodge. If you want to discuss surround sound - the term you clearly know is universally applied - say so. Keith |
#8
Posted to rec.audio.high-end
|
|||
|
|||
Mind Stretchers
Actually I suspect that 4 mikes is enough to establish a
soundfield and am quite sure that 16 would be. That is for the soundfield impinging on one spot of course. The four mikes would be four omnis in a spaced tetrahedron, say 10 inches on a side. The sixteen would be in groups of four coincident ones at the points of the same tetrahedron. These would consist of one omni and three figure 8 ones, the three figure 8 ones being pointed up-down, east-west and north-south. Or, alternatively, four cardioids pointing out from the center of the tetrahedron. This would allow computerized localization of a single sound source generating a sine wave, or localization of the original and reflections of a point impulse source. Of course doing this for a whole orchestra would be an immense and probably somewhat impractical computer programming job. The accuracy would decrease at low frequencies of course. Doug McDonald |
Reply |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Mind Stretchers | High End Audio | |||
Mind Stretchers | High End Audio | |||
Mind Stretchers | High End Audio | |||
Mind Stretchers | High End Audio | |||
It came up, on a mind not clear ... | Vacuum Tubes |