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Re: X-Y -> M-S & Perfect Reversals

Subject: Re: X-Y -> M-S & Perfect Reversals
From: "John Lundsten" lundsten_john
Date: Tue Mar 13, 2007 4:36 am ((PDT))
To: 
Sent: Tuesday, March 13, 2007 4:58 AM
Subject: Re: [Nature Recordists] X-Y -> M-S & Perfect Reversals


At 8:48 PM +0000 3/12/07, John Lundsten wrote:
>JL- I recon (not 100% sure) if you set the decode with the same gain on
>both M&S, unity say. Then boosted / attenuated as needed the L&R output
>channels by the inverse of the amount used on the En-Code, you may (poss)
>get back where you started.

Rob Danielson  Replied
That's what I tried on test #4. Test #3 also without the +6dB gain.
http://www.uwm.edu/~type/audio-reports/M-SDecodeAccuracyTest/+matrix_2ndPlu=
gSettingsUndoFirstNoGain/

JL- I think there IS a difference
I suggested "you set the decode with the same gain on both M&S"
Rather than the offset gains you used
The thinking is:--
The Encode will have the quantity of both M&S one decided in setting the
faders -- An important point to realise is the quantity so defined will go=

in equal amount to BOTH outputs (for M these will be in phase with each) fo=
r
S IDENTICAL QUANTITIES will again be sent but with a polarity inverse on th=
e
right.
So if you were say to just add/sum the encoded signals the S signal will be=

at what ever level you though suitable But with equal amount sent to both
outputs) and it will cancel out But cancellation will only will happen for=

signals that are  in antiphase and are the same level.

best regards
John






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