Hi kenr,

I am using a single M22 placed on the left side of my TV as a vertical center. Works great for me.
My thinking behind this is that since the center carries most of the sound in the movie, it should be your best speaker: and what is Axiom's best bookshelf: the M22.
I've also just ordered another pair of M22's for my front mains and am looking forward to that Holy Grail: a seamless front soundstage.