[LAU] more than 4 channels for listening? Really?

[Martin Leese]

Bearcat M. Sandor wrote:
...
> So the speaker angle is more important than distance? It's the angles
> relative to the listener, right?

Right.

> So a center channel is designed for
> people who are sitting off axis and otherwise not needed?

5.1 was designed for movies playing in
cinemas.  One of the problems with cinemas is
that the owners stuff in as many paying
customers as possible.

This means that many people end up off to
one side sitting close a surround speaker.
Because of this, the centre channel has to be
used to lock the dialogue to the screen.

So, yes, the centre channel of 5.1 was
designed for people who are sitting off axis (or
way in the back of the cinema).

But this is not the only way a centre speaker
can be used.

If you wish, you can derive three new signals
for L, C, R from two stereo input signals, and
use the centre speaker to improve localisation
even for on-axis listeners.  One such system is
called "Trifield", see:
M.A. Gerzon, "Optimum Reproduction Matrices
for Multispeaker Stereo", J. Audio Engineering
Society, vol. 40 no. 7/8, pp. 571-589 (1992
July/Aug.)

If you wish, you can record for three front
speakers.  See:
M.A. Gerzon, "Microphone Techniques for
3-Channel Stereo", Preprint 3450 of the 93rd
Audio Engineering Society Convention, San
Francisco (1992 Oct. 1-4)

A centre speaker is not *needed*, but it can be
useful even for domestic on-axis listening.

Regards,
Martin
-- 
Martin J Leese
E-mail: martin.leese  stanfordalumni.org
Web: http://members.tripod.com/martin_leese/