I recently built a room and tuned it up pretty well, but I'm still getting a nasty reflection from the ceiling I think. I soloed out my overheads and the cymbals sound really harsh and very washy. The toms came through pretty nicely, but all the high end is just bad. I'm using SM81s and they were good zijdian and paiste cymbals, so I don't think they were the problem. I currently have no treatment on the ceiling and was wondering if this is the kind of issue for a diffusor, or absorbsion. If it matters, the floor is vinly tile over concrete that is mostly covered by pretty think area rugs. Any advice would be appreciated.