I have a pair of concept 90 CM1/CM2. The cabinet for the CM1 is a phenolic material and is completely braced in a matrix (the original matrix speaker). The speaker cabinet sounds inert with the unscientific knuckle rap test. I don't recall what the original baffle material is. Is it phenolic, and how thick is it? I know the cabinet must be completely air tight as any air leak causes the woofers to bottom out. I can't see how you could gain much by changing the baffle material.
Granite rings and really is not a sensible choice in my estimation.
Granite rings and really is not a sensible choice in my estimation.