SallySlapCabbage

I'm looking for specifics as to how high, where on wall to mount rear speakers? I bought my husband the RF52 surround package, and while I found specifics for locating the front & center speaker, and can't find specifics on 'location' for the rear speakers. Should they be hear the rear corner of walls - should they be a certain distance from floor? My specifics - 24' long room. 11'-6" wide. 8' high. 120" Screen on 11'-6" wall with 3 rows of theater chairs (each up one platform) from the front wall. Now where do I mount the rear speakers? Any help would be greatly appreciated. Sally