Why is 2 Channel better than multi-channel?

How about three channel? This is something that I have done for about 30 years. The center front can just be an A+B mix, or even a speaker bridged across a stereo amp where one channel is operated out of phase (of course with corresponding reversal of its speaker wires).

In most stereo recordings a solo performer is recorded equally and in phase in the two stereo channels. A center speaker therefore outputs this sound louder than the other two speakers and permits the left and right speakers to be positioned further apart without encountering the dreaded "hole in the middle" problem.

As a bonus, the third speaker increases the SPL (loudness) or gives you the same SPL while driving the speakers less.

I agree with the notion that not having identical speakers does somewhat diminish sound reproduction. I have experimented quite a bit with my settings and found a few things that I believe enhances multi-channel music. I use a B&K reference 30 pre/pro and previously owned a Denon 2802 receiver. The B&K gave me the ability to select specific channels with each listening mode(an option I never had with my Denon). Through trial and error, I learned that listening in 4 channel-mode(no center channel)improved the sound quality of music. I am assuming that this is simply due to the fact that the center channel speaker, a Paradigm Studio CC, doesn't quite match the Studio 80 front speakers. Furthermore, i noticed an audible difference when I set my rear speakers (Studio 40's) to "large" in the speaker setup menu. Since then, I always listen to music in 4 channel mode with all 4 speakers set at "large" and have been much happier with multi-channel reproduction.

Chucknms...In discrete multichannel recordings (SACD or DVD-A) the center channel carries sounds that are simply not there at all in the Left and Right channels. No amount of superb imaging can recover this information.

You really ought to take the time and trouble to get that center speaker set up right.

true...I should have been more specific and said multi-channel music, not necessarily 5.1 discrete as you mention. I would never recommend anyone not include the center channel for SACD or DVD-A playback.

A center channel is not a full range speaker, so, naturally, it would only be fittign to use one in prologic surround theaters.