a lot of good advice above. I built 28 x 17 room from scratch with acoustics in mind. I wanted only minimal wall treatments. +1 on ASC tunable cylinder traps. very versatile and effective. trial and error will definitely get the "low hanging fruit" and produce a noticeable difference. but it is a science to clean up a room while keeping it lively. I had my room tested and identified resonant frequencies and where they existed. Placed absorption & diffusion treatment as needed for the specific problem frequencies. I had everything tested and made through Artnovion. Color & design coordinated with room so it looks beautiful in addition to sounding great (to me). I think a good room treatment is like upgrading every component you have at once. Good luck
