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Beyond stereo?


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47 minutes ago, AJ Soundfield said:

Right, if I got to grade all my own tests I'd be a straight A student. ;)

2 mics are woefully inadequate for any semblance of soundfield reconstruction. That is a physical fact, not conjecture.

At best, one can do a binaural recording for headphones. For speakers and listeners in a room, forget it.

 

I do it with MS miking using figure-of-eight microphones, but one can also do it with crossed figure-of-eights and get really nice ambience using spaced omnis (but this requires a fairly live venue). At any rate, I find two carefully chosen and well set-up microphones are more than adequate to make an ambience-rich 2-channel recording.

George

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20 hours ago, AJ Soundfield said:

Right, if I got to grade all my own tests I'd be a straight A student. ;)

2 mics are woefully inadequate for any semblance of soundfield reconstruction. That is a physical fact, not conjecture.

At best, one can do a binaural recording for headphones. For speakers and listeners in a room, forget it.

 

4 hours ago, AJ Soundfield said:

A 2 mic sample of any soundfield is inadequate to capture both onset and diffuse portions, so that any realistic rendering with loudspeakers can occur. Again, binaural doesn't work with loudspeakers and is inferior to actual soundfield reconstruction rendering methods. I would post all the links yet again, but we are at Einsteins insanity definition here.

The characteristics of the diffuse portion cannot be played back simultaneously with plane wave onsets and be perceived as one would live. That is a physical fact, not conjecture.

 

AJ, from your picture, I'd venture to say that I've been doing live, location recording of classical music and jazz longer than you've been alive. You are entitled to your opinion, but my experiences tell me otherwise. I guess we're going to have to agree to disagree on this point. 

George

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4 minutes ago, AJ Soundfield said:

That's George Clooney not me. Regardless, that's a long time to have not picked up anything regarding basic perception of soundwaves.

I'm not posting opinions. All those links are scientific facts, not opinions, such as you are posting.

If yours aren't, please post the files or links to your 2ch recordings that correctly capture the soundfield so that they can be rendered and perceptually reconstruct the original, TIA.

It is impossible to sample combined direct and diffuse with 2 mics that can then be rendered separately, because they are no longer separate. The leading edges of the planar waves cannot be simultaneously played back from the same speaker producing an unlocalizable diffuse field. If you don't understand any of this, no shame in saying so.

A bare minimum of 4 loudspeakers is required for envelopment as one would have in a live soundfield. Again, scientifically established fact, not fictional opinion.

 

Theoretical "fact" your posting may be, but the reality of the situation is that a very accurate sound field can be captured by two mikes. Now, I certainly agree that you can't capture a complete sound field in such a way that the ambience cues come at the listener from all directions, as in a multi-channel system. That should be obvious to even the most casual of observers of this debate, but the ambience can be captured with two microphones; it just emerges from the two stereo speakers along with the actual sound stage, that's all.

George

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52 minutes ago, AJ Soundfield said:

Correct, but >2 does so much better than 2.

It's really only audiophiles stuck on 2 with their rock music. Nice explanation here: https://www.stereophile.com/asweseeit/1107awsi/index.html

 

We all have our excuses :)

 

How do you know he didn't wet his pants??

 

I've yet to hear a surround recording that imaged well. When I use XY, MS, ORTF, or other  "coincident" mike techniques, I get almost holographic soundstage information. I can close my eyes and point to every instrument in the ensemble. I can tell, for instance, that the brass instruments are not only behind the wood winds, but above them on risers as well! I'm not saying that surround recordings can't do that, but I am saying that I never have heard one that actually did. Most commercial recordings, whether two channel or more than two channel are generally multi-miked with 16 channels or more and a forest of microphones. Such recordings don't image at all.

 

Gordon Holt was one of my closest friends. Yes, he was intrigued by the promise of surround sound. He was also quite disillusioned with the reality of same. In his later years, Gordon did a lot of recording. It was not surround. However, he was quite correct in his assessment of the industry. The original goal of high-fidelity is long- lost.

George

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12 hours ago, semente said:

 

 

@gmgraves only listens to "classical", which also makes for over 90% of what I listen to.

I also attend live recitals on a weekly basis.

 

 

Actually, That's not exactly accurate! I mostly listen to classical music, but I am also a fan of Celtic/American folk music, bluegrass (instrumental only), film soundtracks (Rozsa, Steiner, Tiomkin, Elmer Bernstein, John Barry, etc.) as well as "traditional" jazz (Getz, Davis, Brubeck, and at least a hundred more). I even have a "Beach Boys" CD (but that's it for "rock"). ;)

George

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22 hours ago, AJ Soundfield said:

Me too, minus the Beach Boys.

Any chance of sharing the recordings you made so I can hear this stereo soundfield reconstruction rivaling MCH?

 

I don't think I said that two-channel stereo soundfield reconstruction rivals MCH. I said that two microphones, properly chosen and used can capture both the ensemble on stage and the hall ambience. If I gave the impression that I was favorably comparing two-channel ambience capture with MCH, it was not my intention, and I apologize for any misunderstanding that I might have inadvertently caused. But I will say that use of a simple "Hafler"-style surround hookup can, often, break that ambience information "out" from the 2-channel recording and give a more fulsome presentation because most often that venue information hits the microphones out-of-phase. I used to do that all the time when I had a Dolby logic decoder, or a logic-steered surround decoder during the "quadrophonic" era. But again, it's not real surround and it's effectiveness is purely random. But that effect is the basis for the now obsolete Columbia SQ and the Sansui QS encoding processes. Neither was very satisfying as the SQ system gave a scant 3 dB of separation between front and rear channels while the QS system gave more separation front-to-back while maintaining only 3 dB of separation right-to-left. Neither was adequate. I wouldn't expect a gentleman of your age to have a Beach-Boys CD. I only have one because I liked them as a teen, and thought that Brian Wilson was a genius - still do! :) 

George

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8 hours ago, AJ Soundfield said:

They are nice, but you really need to get out more if that's the best you've heard :)

Odd that they would use them for rears too, since one wants only ambiance around you, as provided by good discrete MCH and upmixing. Those old fist gen MCH SACDs with the sax player behind you were IMO largely why such gimmickry failed.

If you attend live classical, you know violinists don't walk off stage and start playing behind you.

Luckily, I started a separate Ambiosonics thread, where I'm sure the fervent fanboys will be all over it posting, instead of stalking this one about all forms of MCH, i.e more than just 2 speakers.

 

There are lots of good speakers available nowadays: the top model  Radialsthallers (SP?), The Martin Logan Neoliths (and the CLXs - with subwoofers, of course) The Maggie MG-20.7i, the top model Magicos, and on and on and on. But the essential truth is that no one speaker does everything correctly, and I'm a dipole kind of guy. Any speaker that I lust over just has to be either an electrostatic or an isodynamic design. I would be as happy as a puppy with two peters if I had a pair of MG-20.7i's or a pair of Neoliths, but since I'm retired, I have to make do with my Martin Logan Vantages in system #1 and my Maggie MG-0.7s in system #2!

 

Your frustrations with gimmicky surround recordings are a large part of my general disdain for the formats. I rarely heard well recorded surround performances that used the rear channels only for ambience. Don't misunderstand, those type of recordings exist, I'm just not interested enough to seek them out. As I've said before, I spent most of the 1970's chasing "Quadraphonic" sound. At the end of that chase, I was completely disgusted. Later, when Dolby 5.1 and DTS came along, I gave it a brief re-trial. I thought that 5.1 (and 7.1 or 10.1 or whatever) was an even bigger gimmick than quad and while it's probably fine for home cinema (for which it was developed) I find it totally wrong for music on several levels. So, I stick to 2 channel stereo.  

George

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1 hour ago, semente said:

 

I meant that if you put a pair of speakers on the stage and listen from row 7 the amount of reflected sound is much more relevant/significant than at home sitting 2 or 3 metres away from the same speakers.

This is probably why the AR demos worked.

 

I head the AR demos in their Broadway showroom many times as a teen. The AR demos worked because most people who heard them couldn't hear the tape hiss. Being 16 - 17 years old, I could. I could tell which was playing even with my back to the stage. I understand that later, AR caught on and left the tape recorder playing with blank spaces on the tape so when the string quartet was playing, there was still tape hiss so as not to give the game away.

George

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12 hours ago, esldude said:

Yeah I would like to hear that demo especially over Soundlabs.  Quite the setup the Isomike. 

 

I have a lot of the Isomike recordings including the 7 SACD set of Mozart Piano Sonatas with Robert Silverman and I agree, they actually sound excellent and image like gangbusters! Unfortunately, Ray Kimber's setup is wildly impractical for most recording use but I have to hand it to him for figuring out a way to make omnidirectional microphones function "coincidentally". Normally a pair of omnis that close together will give you dead mono. There simply isn't enough difference between the left and the right signal to give one anything else. Traditionally, omnis are placed 12-14 feet apart (further if a center channel mike is employed as in the Mercury Living Presence recordings by C. R. Fine) for "stereo". But by using that huge, heart-shaped baffle between them, he gets the phase-coherent stereo of coincident miking and the super-flat frequency response of omnidirectional mikes. Best of bothe worlds! 

George

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