I switched my M22's to the other side to see if the problem has anything to do with wiring or anything, and the problem still exists with the specific M22.
After doing some painful exploration at loud volumes with my ear next to each driver, I find the problem to be most prevalent when listening through the rear port into the back of the tweeter. The rattling noise is prevalent with almost all material when one listens through the rear port. So I have put in a call to Brent to see if he can help me out. I already have an extra tweeter, so I may try installing that with Brents advice.
