DL, if the narrow area usable with the phantom center is acceptable, continue to use it. If it isn't acceptable, get a separate center channel speaker which matches up well with your M22s. I believe that this will more likely be a vertically positioned M2( possibly upside-down) rather than a VP100.

Also, more separation of your M22s would be desirable. Couldn't the entire setup except for the left M22 be moved 2-3 feet to the right?

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Enjoy the music, not the equipment.