I would not use 4 M22's, as i think you are mentioning, two for the left/right, and 2 more closer to the tv for center. I would just allow the left/right m22's alone to create what is called a "phantom" center. Many have achieved fairly good results using this method when they can't accomodate a regular center. If you have ever listened to regular 2 channel stereo CD's, the singers voice usual appears to be coming from dead center, this is similar to when using "phantom" center for movies. Another option is to possibly mount an VP100 or similar above the screen angled down slightly, or possibly one of the "onwall" or "inwall" versions.
