Center channels: why only horizontal arrays?

Esthetics and assumed ignorance of acoustics (on the part of the typical user) are the only reasons. A conventional vertical array is superior and preferred by many who use three identical speakers for the front L/C/R.

Kal

aesthetics and practicality. most people just don't have the space for a vertical speaker under their tv.

i think they both screw up the imaging and run the risk of directionality myself.

i'm getting a funny image in my head, though, with the way you've got "aesthetics" spelled there, Pmcneil - i'm seeing a bunch of buddhist monks watching movies on a nice home theater system, but it has a horizontal center channel because they've renounced the luxury and materialism of a vertical center channel...

(i'm definitely not one to nitpick on spelling, it just happened to give me a chuckle there!)

Its just more practical for the average consumer,I have tried them both ways and for a center application there is often no huge difference worth worrying about in sound quality.