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#81
Posted to rec.audio.high-end
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Cable sound. Real after all?
On Sun, 15 May 2011 10:34:11 -0700, Gary Eickmeier wrote
(in article ): "Audio Empire" wrote in message ... You absolutely need the center mike if you are using widely-spaced omnis, if for no other reason than to avoid an obvious hole-in-the-middle effect. You only need a center speaker if you have a three channel playback (such as some releases of Mercury and RCA Red Seal 3- channel recordings on SACD. But, then you need three amps and three preferably identical speakers. Step back a minute on that one. I have found that some speaker/room combinations exhibit the dreaded hole in the middle, or stretched soloists, due to some reasons I give in my paper, but the idea is that if you screw up the speaker placement you can have two "clumps" of sound at the right and left, with no solid center that is well focused. A center speaker eliminates most of that problem. Obviously. But that's another story. Of course, people with poorly set-up playback systems (like speakers in corners on the opposite sides of the room from one another) can create problems that don't exist on the recording itself, but that has nothing to do with the competence of the recording. The playback end can be so incompetently set up, or in a room with such bad acoustics that the best recording in the world will sound lousy. I used to know a recordist who had his speakers set up as I describe, above. To "compensate" for the fact that his speakers were 12 ft apart, he would turn the pan-pots on mixer to 10 and 2 O'clock respectively. ON his playback system, they sounded fine, on a properly set up speaker system, they might as well have been mono. I could never convince him that this was "wrong thinking". One records properly by using full separation, not by optimizing the pickup for a single flawed playback setup. Well, joy of joys, I just happened to make a single point stereo mike recording at the same time, for backup and/or comparison. Haven't even downloaded it yet, the first one took so much time and was so successful. Maybe could make a special test recording where i fade between the two techniques and see what happens. If you did the latter correctly, you'll find that it produces a superior stereo. I cannot say that the single point stereo mike was perfectly placed, no. So the comparison won't be real fair, but it was there for backup, so I might learn something from it anyway. Just tell us which recordings are yours, and we may own them already. What is your name? I didn't say that they are commercial recordings. I was the archival recordist for a famous symphony orchestra for many years, Most of the Jazz stuff I recorded was for a National Public Radio Network series called "Jazz Alive" as well as having recorded the entire San Francisco Jazz Festival for three years running. Most of my recordings these days are for civic musical groups and institutions like the Stanford University Jazz Band, The Stanford Winds, and the Stanford Symphony, plus countless jazz groups who want their performances preserved. Some of these things I was paid for doing, and some I did just for my own amusement. I would love to hear something, if you can make a disc or upload something. Send me an e-mail with your address. I think that I can send you something.... Read your blog - very complete and good. I may still have a few questions, because I have just gotten serious about audio recording and have the equipment now to do some innocent experiments. There is nothing like hands on experience. (I have been a video professional for 20 years now, after Air Force retirement.) My degree is Industrial Design. Gary Eickmeier Glad you enjoyed it, Gary. |
#82
Posted to rec.audio.high-end
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Cable sound. Real after all?
"Audio Empire" wrote in message
... I currently use a single-point stereo mike for much of my recording these days where one mike head rotates with respect to the other (Avantone CK-40) http://avantoneaudio.com//ck40.htm I use it in an A-B configuration either in the cardioid mode or (depending upon the situation) crossed figure-of-eight. Lately I have put together a isolation matrix that allows me to do M-S (one mike in cardioid pattern, facing the ensemble, and the other mike at 90 degrees to the front "firing" cardioid and set to the figure-of-eight pattern. The Front + Side and Front - Side matrixing is done in the mixer (it takes three mike channels to do this, but the results are worth the extra mixer input). The mike sounds excellent and easily betters my Sony C-500s. Have you found that this configuration can seem to encode a surround sound feeling when played thru a Dolby surround type decoder? I think it depends on the rear sound being out of phase and front center being in phase, and then all angles in between come out where they belong. In Toole's new book, he made an extremely interesting observation about coincident miking. He described an experiment wherein the Ambisonics Soundfield microphone, which I believe is the world's most coincident microphone, when played back anechoically produced IHL - in-head locatedness, rather than a surround effect. To me, that means that playback depends on the real acoustic space of the room to develop directional perception. The direct sound is not enough. Take from this what you will and talk amongst yourselves.... Gary Eickmeier |
#83
Posted to rec.audio.high-end
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Cable sound. Real after all?
On Sun, 15 May 2011 18:25:33 -0700, Gary Eickmeier wrote
(in article ): "Audio Empire" wrote in message ... I currently use a single-point stereo mike for much of my recording these days where one mike head rotates with respect to the other (Avantone CK-40) http://avantoneaudio.com//ck40.htm I use it in an A-B configuration either in the cardioid mode or (depending upon the situation) crossed figure-of-eight. Lately I have put together a isolation matrix that allows me to do M-S (one mike in cardioid pattern, facing the ensemble, and the other mike at 90 degrees to the front "firing" cardioid and set to the figure-of-eight pattern. The Front + Side and Front - Side matrixing is done in the mixer (it takes three mike channels to do this, but the results are worth the extra mixer input). The mike sounds excellent and easily betters my Sony C-500s. Have you found that this configuration can seem to encode a surround sound feeling when played thru a Dolby surround type decoder? It might, but I'm strictly a two-channel guy. It's hard enough (in my estimation) to get two-channels "right" to waste any of my energy on surround, but that's MY taste. If I had any clients clamoring for surround, I might give it a whirl, but so far nobody's asked. I have Dolby surround on my home theater setup, of course, but that's in another room. I think it depends on the rear sound being out of phase and front center being in phase, and then all angles in between come out where they belong. Were I to try that, I would set the "M" mike in omni or even figure-of-eight pattern to pick up more of the room acoustic. Of course, that's not really practical in a club or concert hall where people (other than the musicians and recording personnel) are present. In Toole's new book, he made an extremely interesting observation about coincident miking. He described an experiment wherein the Ambisonics Soundfield microphone, which I believe is the world's most coincident microphone, when played back anechoically produced IHL - in-head locatedness, rather than a surround effect. To me, that means that playback depends on the real acoustic space of the room to develop directional perception. The direct sound is not enough. An Ambisonics mike is NOT in any way a simple coincident pair. It consists of 4 super or hyper-cardioid mikes arranged in a closely spaced tetrahedron and marked W. X, Y, Z. and all are pointed in a direction tangental to the sides of the tetrahedron. The system requires a "UHJ" encoder to matrix the 4 mikes to create al LF, RF, LR and RR "channel" and might indeed sound as if you, the listener had that tetrahedron inside your head, because obviously it requires room reflections to work WITHOUT a UHJ decoder. Did Toole say anything about the differences between the recording played with and without a decoder in an anechoic chamber? Take from this what you will and talk amongst yourselves.... Gary Eickmeier |
#84
Posted to rec.audio.high-end
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Cable sound. Real after all?
"Gary Eickmeier" wrote in
message PHOOEY! You don't want to make stereo recordings with a coincident mike! Stereo operates on a macroscopic scale, not "at the head" of the listener. This being the case, if the images are formed in the room from speakers located with substantial geometric similarity to the live instruments, you may want to place the microphones near those instruments. I just finished an experimental recording to help prove my ideas on the recording end. I had always used the convenient single point stereo microphones for video work or concert recording. But there wasn't a very satisfactory stereo effect from them, because they are placed at only the one point in the room. There is a hidden agenda in recording, and that is what our mutual friend Dave Clark calls "Dereverberation". Dereverberation is something that our perceptual system does for us all of the time and in such a way that we are usually uncconscious of it. It is a way to identify what some call "the cocktail party effect". It is a subject of significant amounts of research at this time because of how pervasively it affects communcations systems. The basic idea is that for whatever reason, our perceptual system tends to remove or attenuates the acoustics of the room that we are listening in. The inherent problem with recording is that our recording systems don't dereverberate like our ears do. So, our recordings can't be very effective at delivering that "you are there" experience. In a way, our ears do their part. They dereverberate our listening rooms which facilitate us hearing through our listening rooms to hear the acoustic of the room the musical performance happened in. However, we currently have no way to make a properly dereverberated recording. My theory sez that Telarc was right in using three spaced omnis up front, spread across the soundstage. I have my own ideas about positioning them, so I needed to get a multichannel recorder and several omni mikes to try it out. I bought the Zoom R16 eight track digital recorder. I already had several of the cheap little Sony lavalier condenser mikes that we use for video, so that is what I used. Positioned them about 8 feet apart at center, half left, and half right and as far as I could comfortably get, about 6 feet, from the front row of players. Since you have enough channels, it seems to me that you should make both spaced and coincident recordings at the same time. I don't know which lav mics you have, so I don't know how they shape up as good vehicles for experimentation. A transfer to Audition, a little EQ, a mixdown to stereo (for now), and the result was so fantastic I was sitting there crying like a baby it worked so well. Spacious, even imaging all across the soundstage, great dept imaging, pinpoint when there was a solo, just spectacular. One key component of any investigation is comparisons between different approaches to the same problem. Maybe I can take the moderators' advice and upload some files with Usendit and post a link. The way that people solve this problem is that they obtain some public space on the web, and post a link to it. There are many sources of public file space. For example, Comcast provides me with 1 GB of file space to load and reveal to the public at will. There are also third party suppliers of this kind of space, many who provide a fair amount of public file space at no out-of-pocket charge. Please search google for file sharing. Just too bad you can't hear it on my system. If you are going do something with general interest, it has to sound at least acceptable on people's current systems. The core of the problem is not just the reproduction, it is also in the recording. |
#85
Posted to rec.audio.high-end
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Cable sound. Real after all?
"Sebastian Kaliszewski"
wrote in message Well, not. When you EQ a speaker (esp. multi driver one) radiation pattern changes as well (partly due phase changes, but not only due to them). To clarify: Depends what you eq. If you eq the signal paths to individual drivers, then you can definately cause changes in the speaker's radiation pattern. If you eq the whole system, that is eq the input to the speaker system, then there are no changes to the speaker's radiation pattern as long as there is only one speaker in the room. If you have two speakers in the room and apply the same equalization to each of them, then it is far less likely that there will be changes to the speaker's radiation pattern. |
#86
Posted to rec.audio.high-end
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Cable sound. Real after all?
"Audio Empire" wrote in message
... Were I to try that, I would set the "M" mike in omni or even figure-of-eight pattern to pick up more of the room acoustic. Of course, that's not really practical in a club or concert hall where people (other than the musicians and recording personnel) are present. I am actually after hearing some audience in the recording. I have always hated the way stereo folds back the audience into the stereo image, and have been searching for a way to hear them back with me and behind me, like in real life. In Toole's new book, he made an extremely interesting observation about coincident miking. He described an experiment wherein the Ambisonics Soundfield microphone, which I believe is the world's most coincident microphone, when played back anechoically produced IHL - in-head locatedness, rather than a surround effect. To me, that means that playback depends on the real acoustic space of the room to develop directional perception. The direct sound is not enough. An Ambisonics mike is NOT in any way a simple coincident pair. It consists of 4 super or hyper-cardioid mikes arranged in a closely spaced tetrahedron and marked W. X, Y, Z. and all are pointed in a direction tangental to the sides of the tetrahedron. The system requires a "UHJ" encoder to matrix the 4 mikes to create al LF, RF, LR and RR "channel" and might indeed sound as if you, the listener had that tetrahedron inside your head, because obviously it requires room reflections to work WITHOUT a UHJ decoder. Did Toole say anything about the differences between the recording played with and without a decoder in an anechoic chamber? Yes of course. It is all on page 286. I can quote the final couple of sentences: (He first mentions that the system requires you to be at one point among the speakers, and if you lean forward, back, right or left, the imaging biases that way) "All of this should be no surprise in a system in which the mathematical solution applies only at a point in space, and then only if the setup is absolutely precise in its geometry and the loudspeakers are closely matched in both amplitude and phase response. Room reflections absolutely corrupt the theory. So what did it sound like in the anechoic chamber? It sounded like an enormous headphone; the sound was inside the head. When the setup was moved to a nearby conventional listening room, the sound externalized, and all previous comments apply." This is an important piece of the puzzle for me, and indicates that I am correct in saying that stereo in general should not work with the direct sound alone. You are all familiar with how some setups with highly directional speakers require you to be nailed to the sweet spot. If you go a step in either direction, you will be listening in mono (to the speaker on that side). A correct theory, or presentation, would permit you to wander freely in the listening room, right, left, closer to the speakers or farther away, and get a feeling very much like if you moved around at the live event. This can be accomplished with a correct radiation pattern and speaker positioning. And hey, not a lot of sound killing materials near the speaker end, so that the reflected sound is of the same frequency response as the direct. Does some of that sound familiar, in a Linkwitz kinda way? Gary Eickmeier |
#87
Posted to rec.audio.high-end
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Cable sound. Real after all?
On Mon, 16 May 2011 06:54:03 -0700, Gary Eickmeier wrote
(in article ): "Audio Empire" wrote in message ... Were I to try that, I would set the "M" mike in omni or even figure-of-eight pattern to pick up more of the room acoustic. Of course, that's not really practical in a club or concert hall where people (other than the musicians and recording personnel) are present. I am actually after hearing some audience in the recording. I have always hated the way stereo folds back the audience into the stereo image, and have been searching for a way to hear them back with me and behind me, like in real life. In Toole's new book, he made an extremely interesting observation about coincident miking. He described an experiment wherein the Ambisonics Soundfield microphone, which I believe is the world's most coincident microphone, when played back anechoically produced IHL - in-head locatedness, rather than a surround effect. To me, that means that playback depends on the real acoustic space of the room to develop directional perception. The direct sound is not enough. An Ambisonics mike is NOT in any way a simple coincident pair. It consists of 4 super or hyper-cardioid mikes arranged in a closely spaced tetrahedron and marked W. X, Y, Z. and all are pointed in a direction tangental to the sides of the tetrahedron. The system requires a "UHJ" encoder to matrix the 4 mikes to create al LF, RF, LR and RR "channel" and might indeed sound as if you, the listener had that tetrahedron inside your head, because obviously it requires room reflections to work WITHOUT a UHJ decoder. Did Toole say anything about the differences between the recording played with and without a decoder in an anechoic chamber? Yes of course. It is all on page 286. I can quote the final couple of sentences: First of all, it's NOT a pair. It's four microphones, not two. Therefore it has NOTHING to do with what we're discussing. Gary Eickmeier |
#88
Posted to rec.audio.high-end
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Cable sound. Real after all?
On Mon, 16 May 2011 06:54:03 -0700, Gary Eickmeier wrote
(in article ): "Audio Empire" wrote in message ... Were I to try that, I would set the "M" mike in omni or even figure-of-eight pattern to pick up more of the room acoustic. Of course, that's not really practical in a club or concert hall where people (other than the musicians and recording personnel) are present. I am actually after hearing some audience in the recording. I have always hated the way stereo folds back the audience into the stereo image, and have been searching for a way to hear them back with me and behind me, like in real life. Believe me, even with a coincident pair, you'll hear MORE than enough of any audience. But tastes vary. I want to hear to hear the musicians with as little outside interference as possible. |
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