@Bridgman - thanks for the response. We have two local dealers here who do installs so they have experience. I am waiting to hear back from one of them on the issue.

I actually thought about framing the wall out 6 inches. That would do the trick. I might just go with the on walls. Having owned both M22 on wall and in walls I prefer the on walls. The WAF is just a little lower.

Temp.setup - 2.1 - Denon 1713 AVR, Denon 1713 BRD, Paradigm Cinema 200, and Monitor Audio 360 Sub