I have a tricky problem of a room 11'-8" x 11'-11" x 8'-0" high that is packed with equipment (as in Audio Hoarding) also books and cd's on shelves, and I am trying to tame low freq modes (like 70hz). Room is used as control room for mixing. Not much room on the walls (expect up high) I was thinking of building 8" roxsul bass trap panels with floor mounting than can be moved out of the way, say, to open a closet door or something. Would they work? Do people use moveable absorption?