Today I received via freight the Paradigm Titans that I am using for rears. The wife is requiring me to wall mount them, and the guy I bought them from sent me the appropriate Paradigm brackets for doing so. Problem is, wall space it limited as the rear wall is mostly a sliding glass door with some blinds. The Titans are larger than I anticipated. Anyway, I have one decent option, turning them on theirs *sides* (rectangular speakers) and mounting them in the space above the curtain rod. Is there any rule that you cannot mount speakers on their sides, or upside down for that matter? I am not asking if this will be optimum acoustically, just whether it will TOTALLY screw up the acoustics.