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Re: M/S recording setup

Subject: Re: M/S recording setup
From: "James Shatto" wwwshadow7
Date: Tue Aug 17, 2010 6:11 am ((PDT))
>
> --- On Tue, 8/17/10, Dan Dugan <> wrote:
>
> From: Dan Dugan <>
> Subject: Re: [Nature Recordists] M/S recording setup
> To: 
> Date: Tuesday, August 17, 2010, 12:09 AM
>
>
> What Rob said, except I think it would be clearer to use the
> term "matrix" rather than "encode."
>
>
> James wrote,
>
> > ...if you mix to stereo in the field, even though you can
> > derive most of the non-stereo version in post.  You lose
> > resolution by doing do.  So your 44100Hz sample is for all
> > intents 22050Hz once you split it apart.  Which isn't as
> > useful when you need to do severe edits like EQ or time
> > adjustments to sync with another device.
>
>
> I don't understand that. A 44.1KHz stereo interleaved WAV
> file (also called "poly" because any number of channels can
> play) splits into two 44.1KHz mono files with no loss. The
> utility "Interleaver" does this easily. Stereo files are
> just as long in playing time but twice as big in storage,
> because they have all the data for two channels.
>
> All my stereo and 4-channel files get split into mono files
> by Pro Tools when I load them in for post. No losses.
>
>
>
> -Dan

22050 was a bit of an exaggeration on my part.  But, I'm talking about taki=
ng a file that was already matrix'd into stereo (LR) from MS to derive the =
original MS raw tracks.  You have a finite set of bits per channel.  When y=
ou apply other bits you lose bits of information.  It may not be enough los=
s to be audible.  But you have less information than you had or would have =
had before the audio was matrix'd.

Deriving M + S from L + R is what I was hinting towards.

Converted to mono by combining L and R into ONE channel, gives you M, becau=
se +S and -S cancel each other out.

M plus L or R into one channel gives you (+ or -) S.

BUT you've done many edits from the original files to get to that point, le=
aving you less information than you would have had, had you just recorded M=
 and S to their own tracks and matrix'd to L and R in post.  Yes you can de=
rive M and S from L and R, but quality wise you've lost something in the tr=
anslation.  If you need to do massive EQ and widen or narrow your stereo im=
age, you would have had higher quality if you had recorded M + S and not L =
+ R.

- James










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