I don't really understand the "wall of sound" mentality.
Once you're sufficiently reproducing the required amounts of bass, midrange and treble (i.e., flat frequency response), what does adding more speakers (coming from the same direction) offer except messed up imaging?
I've tried it both ways. The imaging isn't messed up, as long as all the speakers on the same channel are vertically aligned. (That would be like saying the imaging of the M80 is messed up because there are 2 of each speaker.)
With a single M22, I can tell the sound is coming from the M22. With 2 vertically aligned M22's, it sounds like the whole wall is exploding with sound. (Good just got better.)
That's another possible option for the person that started this thread. Mount 2 M22's on top of each other for L/R and use a VP160, mounted in the center of the screen for the center channel.
