The most common advice is to use absorption. However, if you have sufficient distance from the walls to the MLP, diffusion can also be used. I chose diffusion myself, as I don't like the smothered sound of a lot of absorption in my HT. My studio leans towards the dry side of neutral, and I didn't want that for my HTs. I prefer a more open sound at home, so the only absorption in my HTs is on the front and back walls and a very thick pad with shag carpet on the floor.So, reading back the suggestions I get quite confused. Should I use broadband absorption at first reflection points, or diffusion, or both, or nothing? I would not mind increasing clarity a little now that the centre image is fixed.