I had my entire room's ceiling sprayed 1" thick with bleached-white cellulose insulation fiber. This is the same gray stuff found on warehouse ceilings, etc. It improved the echos & reflections considerably & was not very expensive, although it was quite a messy install. The cellulose worked well enough that I didn't have to completely hide the beautiful hardwood floor under full carpeting; a large wool deco. rug centered in the room does nicely. Also hung some artwork and various hook rugs on the walls all around, plus the curtains & stuffed furniture all adds up to some pretty decent room treatment and looks quite natural compared to the various treatment contraptions