Why not use mains as centers

Right, Bob, except I did that a few years back. ;-)

I recall being annoyed at the repetition of basic articles in the hobbyist mags every 2-3 years back when I was an avid reader of the audio and photography mags. Now, I realize that there are new readers coming on board all the time and they never saw the previous publications.

Still, today, everything is archived on the Internet. Unfortunately, no one new knows to search for that stuff until something becomes an issue for him.

Kal

In specific, horizontal speaker arrays are fundamentally flawed and that is why you see so few of them used for stereo or main channel speakers.

Absolutely agree. I have no ATC center channel. There is a reason and it is not budget. There is also a reason that studios use the same speaker for center channel as they do for the other channels. Also studios align the speakers vertically (midrange and tweeter must be at the same height as L and R). The whole HT horizontal home center channel thing is a compromise for off axis listeners - they benefit but overall everybody loses a bit from this configuration. Obviously the TV screen makes this comprise necessary, however, for those who rarely watch movies with a crowd their is a compromise which is better IMHO: phantom center!

>Is there a reason I should'nt use two good bookshelfs or smaller towers for my center if I have two center outputs and available amp channel?

You don't want to use two because one will have more uniform power response and off-axis behavior than two.

I use a full-range main speaker as a center channel....and it rocks. I use an infinity Kappa 9 laid horizontally as my center channel.