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1. Re: M/S recording setup

Subject: 1. Re: M/S recording setup
From: "James Shatto" wwwshadow7
Date: Sun Aug 22, 2010 1:16 am ((PDT))
I guess it depends on how you do the math.=A0 Not a real world test by any =
means, but I synthesized some stuff to better clarify my line of thinking.=
=A0 Not that you'll have conditions where M and S have matching phase + amp=
 + frequency (much) in practical applications.=A0 But...

http://home.earthlink.net/~shadow_7/MS_TEST.sh

It uses bash and sox to synth some pitches across a broad range.=A0 Kept th=
e root and 5th of a chord unique to M and S.=A0 Mixed a common tone (the th=
ird of a chord) between the two tracks and the results were interesting.=A0=
 -S for the right channel completely cancels out the 3rd of the chord on th=
e right channel.=A0 When going from M and S to L and R.=A0

Going from the generated L and R back to M and S.=A0 And +S and -S don't ca=
ncel each other out anymore.=A0 And to make matters worse the 5th which was=
 unique to M (and NOT S) is the result of trying to cancel S out.=A0 Not th=
at it's a real world practical test.=A0 And I probably didn't get the math =
just right.=A0 But it seems a bit interesting to me.=A0 Assuming that it's =
not some software quirk with sox or my math.=A0

I was only expecting to find some minute differences in the waveforms of th=
e derived versus original tracks when I started out.=A0 And maybe some loss=
 of frequencies in the upper bands.=A0 Needless to say that the quirks I fo=
und were VERY audible.=A0 The timing and other variances of actual M/S woul=
d likely not yeild the same results.=A0 Especially if M and S are NOT mixed=
 at unity gain.=A0 But it should lend some credibility to recording the M a=
nd S tracks and not the L and R tracks in the field.=A0 If you intend on do=
ing any editing IMO.

- James


--- On Fri, 8/20/10, Marinos Koutsomichalis <> wrote:

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