My stereo is in a second living room. It has a lot of square feet of hard surfaces opening in to a kitchen and dining with more hard surfaces. There is no way furniture could solve my reverberation/decay issues. Nyal of Acoustic Frontiers located in the San Fransisco area helped me, remotely. He had me draw detailed "blueprints" of my room and kitchen/dining. We used google file sharing for REW measurements I performed. We addressed the frequencies first (below the Schroeder frequency), trying to position a pair of REL subs. They could not solve my bass issues and were replaced by JLA fathom subs and crossover.
He designed an acoustic panel implementation using a few different manufacturers, including wall and ceiling absorption panels and wall-hanging bass traps/diffusers. I picked out fabric, picture and color, etc and installed them myself. A laser level is a great tool for this and for finding the center of the room. Nyal cautioned me about the acoustics from the kitchen, but I did not fully implement his design for it. He was right. I have since placed an acoustic room divider, which looks dumb but works well. Aesthetically it turned out as well I could expect in my situation. Nyal’s expertise was of great value and relatively low-cost compared to panels and subs. I highly recommend him for those in that budget range.