[Tom McCreadie]

Gary Eickmeier wrote:

Tom - might be some confusion in your description of reversed channels to
the rear. As I understand it, the rear info in DPL is mono, not stereo, so
there can be no reversed channels.

The additional remarks on the lateral-image-reversal quirk of Blumlein was
actually addressed to plain vanilla Blumlein, played back over two speakers,
with no DPL processing whatsoever involved. My apologies for throwing that
unnecessary confusion into the discussion.

The lateral reversal phenomenon I referred to can best be illustrated by the
following scenario: Take 4 performers A...D stationed at direction angles of A
11:00 , B 11:30, and C 12:30 and D 01:00 - o'clock w.r.t. the mic mainpair. The
resultant imaging from a two-speaker playback would be in the following
sequence:
- from a Jecklin Disk: L... - A - B - C - D - ...R
- from Blumlein also : L... - A - B - C - D - ...R

But if players A and D elected to stand on the other side of the array, at
respective angle positions 07:00 and 05:00 -o'clock, their images would appear
in the following sequence:
- from Jecklin Disk, still: L... - A - B - C - D - ...R
- but now from Blumlein: L... - D - B - C - A - ...R ( "A-D reversal")
N.B. That lateral image reversal phenomenon - which may not be a big deal
anyway, unless you have important sound sources behind the array - isn't
confined to Blumlein; it can rear its head with supercard XY, cardioid MS etc. .
(rear sector angular width will vary with array set-up parameters.)
--
Tom McCreadie

Q. What's the most dangerous sport in the UK?
A. Rugger mortis