I know its preferred not to mix audio brand types so a sonic consistency is maintained but here is my question. I only have a 5.25" space for a center channel speaker in my TV stand and am thinking of buying a Martin Logan Motion 6 center to accompany the Klipsch R-15M (which I currently have). This new center would replace the center that came with the Klipsch quintet speaker system. My size limitation of the center channel does not give me a lot of options. Any thoughts on all this for my home theater system? Thanks.