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4. Re: Decca Tree?

Subject: 4. Re: Decca Tree?
From: "Lou Judson" inaudio
Date: Tue Sep 2, 2008 8:48 am ((PDT))
I do not wish to argue this further, but this is not true. Simply not
true. S cancels out after conversion to stereo and summing to mono. I
do not insists on being right but protest the misinformation here...

<L>

On Sep 2, 2008, at 8:43 AM, Scott Fraser wrote:

<<I don't think so, Scott. The side capsule is completely out of phase
left and right, thus they cancel completely, unless some manipulation
has been done on it that offsets the balance.>>

Undecoded yes, the left & right components of the S channel are out
of polarity. However, once MS has been decoded we now have L & R
channels which are mathematically identical to XY components. Thus
when they sum there's no longer any phase cancellation, just simple
addition of the two elements. If the ambience changes when summing
decoded MS it's an indication of the physical offset of the two
diaphragms. There is always some cancellation at the top octave,
10kHz & above, since we can't get the diaphragms closer than about an
inch apart, but that has a minimal effect on the overall frequency
response & portrayed ambience.

Scott Fraser




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