To answer the question you actually asked -- I repeat -- try something like the ASC Matrix Panel or RPG BAD panel. They are made for the application. The GIK Alpha line might work, too, but I’ve not tried it in that application (very close to the listener).
Unlike "real" diffusers, you can speak right into these products and not get phasey or unpleasant sound. And unlike broadband absorbers, they don’t create acoustic dead spots. If you are going to sit near the back wall, I don’t think you will do better.
Unlike "real" diffusers, you can speak right into these products and not get phasey or unpleasant sound. And unlike broadband absorbers, they don’t create acoustic dead spots. If you are going to sit near the back wall, I don’t think you will do better.