Can a multi-miked recording preserve phase?

Posted by phenderson on November 1, 2000 at 17:56:33

In Reply to: Re: Miles is quite right! posted by john curl on October 31, 2000 at 16:24:00:

Many years ago Mr. Carver made the rather obvious point that if a sound is recorded from two points that are not equidistant from the sound source, and the two signals are then overlaid, there will be a time delay, and, barring coincidence, a phase discrepancy between the earlier-arriving signal and its "ghost." He designed his "Sonic Holography" circuit to correct for this, but, unfortunately, the phase incoherence in a typical recording is too complex to be unraveled by a simple circuit. If you imagine a symphony orchestra, even with only two nearby microphones, there will be a phase disagreement in the highs which varies for each instrument according to its placement; with multiple microphones you get phase stew. I own one of Mr. Carver's Sonic Hologram generators, and it does produce remarkable effects if your speakers have even average imaging capability: namely, you will hear guitarists positioned in the bathroom and drummers outside the living room window etc. Not "faithful" but amusing. On some recordings, the effect is very positive. Ingenious if flawed. Another try is the McShane Ambience Recovery System used in the late top-of-the-line Fried Valhalla system, and another Fried model just below that. I have heard this and it is a lot less obvious than the Carver system, but also less dramatic. (The Fried speakers were excellent, it's a shame they failed to catch on.) In any case, while there can be no objection to preserving phase as it passes through the component chain, the odds that it is corrupted from the outset would seem to be pretty high. In particular, I don't see any rejoinder to Carver's point about relative placement of microphones (not to imply it's an original point with him.)

As for Harry, you should have had him listen to your phono preamp through Vienna Mozarts (at fairly close range.) Yes, I know, they weren't around then. (And despite the joking, I think well of them.)

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Follow Ups Full Thread

Topic - Absolute Phase - ws 06:05:52 10/30/00 (22)

There is no way to test... - clarkjohnsen 07:52:12 10/30/00 (16)

Re: There is no way to test... - ws 09:07:40 10/30/00 (15)

Balderdash - phenderson 16:20:43 10/30/00 (14)

No such thing as "in correct phase"! - clarkjohnsen 08:58:55 10/31/00 (1)

"Wood Effect" available online - where? <nt> - Arbelos 15:02:14 11/1/00 (0)

Re: Balderdash - Myles B. Astor 04:54:00 10/31/00 (2)

You should always know whether it inverts phase... - Inm8 17:19:00 10/31/00 (1)

Re: You should always know whether it inverts phase... - Myles B. Astor 17:56:08 10/31/00 (0)

Re: Balderdash - A. Welter 01:48:36 10/31/00 (8)

Re: Balderdash - Myles B. Astor 05:00:52 10/31/00 (3)

Re: Balderdash - A.Welter 22:12:17 11/1/00 (1)

Re: Balderdash - Myles B. Astor 04:38:26 11/2/00 (0)

Re: Balderdash - rcrump 06:42:58 10/31/00 (0)

Re: Balderdash - Myles B. Astor 04:58:37 10/31/00 (3)

Miles is quite right! - clarkjohnsen 08:44:11 10/31/00 (2)

Re: Miles is quite right! - john curl 16:24:00 10/31/00 (1)

Can a multi-miked recording preserve phase? - phenderson 11/1/0017:56:33 11/1/00 (0)

Re: Absolute Phase - Romy 06:29:19 10/30/00 (4)

Re: Absolute Phase - ws 09:06:04 10/30/00 (3)

Re: Absolute Phase - Romy 09:55:41 10/30/00 (2)

Re: Absolute Phase - ws 10:23:57 10/30/00 (1)

Re: Absolute Phase - Romy 10:52:23 10/30/00 (0)

Follow Ups

Can a multi-miked recording preserve phase? - phenderson 11/1/0017:56:33 11/1/00 (0)

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