Iain Churches wrote:

"Phil Allison"

** Listening on headphones while operating the "stereo-mono"
switch on my amp:

Segment 1 is plain mono.

Yes.

Segment 2 has some ambience coming from L & R of center -
which disappears entirely when switched to mono.

That was the producers' brief, total mono compatibility with
no change in the original sound.

Segment 3 in simply out of phase - the level drops by over
15db

Yes. It was done to illustrate the importance of the ratio
of centre to side signals. Normally the centre signal needs to
be some 6 to 10dB stronger. In segment 3 the levels are
equal.


** To quote a famous TV alien: "that does not compute".

Such a strong cancellation requires R to almost exactly equal -L.

A small delay plus phase reversal could NOT produce that.

Do the math....



In fact, I hear swishy cymbals on all three segments.

That's probably due to the low res of the track which I
posted.


** IMHO MP3 sucks.

Low bit rate MP3 sucks to the max.

Invented by a deaf Kraut code scribbler and loved only by film industry pukes - who have always accepted totally crap sound as just fine.



..... Phil