"Smarty" wrote in message ...

Why did you make the statement that a 90 degree phase shift
added to the rear discrete audio channels in any encoder which
mixes down to 2 channels, to use your exact words, "removes
ambiguity between front and back signals" ?

In the early days of matrixed surround, Michael Gerzon wrote an article for a
British hi-fi magazine explaining what happened as sources were panned from
front to rear, and a resulting directional ambiguity (with respect to the
encoding). I cannot find the article.

However, a brief search turned up the following. Note Section 8, in
particular.

http://www.michaelgerzonphotos.org.u...20COMPLETE.pdf

By the way, Scheiber mentions the need for phase shift in the patent I
referred to, though I don't believe he goes into any detail.