I have a Mesa Single rectifier and a 4x12 rectifier cab. due to the size of my room the back of the amp is about 20 inches away from a wall and my entire room is tile. i get a very bright harsh sound at loud volumes. if there anything i could in the back of the amp to help sound quality ? Thanks for the input.
Take it out of the tile room? O.o Or maybe re-EQ it for loud volumes. Or set it on a piece of carpet. Try beam blockers too (google it).
put up some egg crate? anything to dampen the sound should help, rugs, carpeting, etc.