In my last (late, lamented) home I had a dedicated listening room w/carpet over concrete floor and framed walls. This is the best combo I've found. In a prior home, I had two concrete walls with a concrete floor. The floor is great, particularly w/a turntable. The walls were more problematic.
To deal with the wall issues, you may wish to follow the process I followed:
Pick up a whole bunch of absorbtive wall treatment (there are a lot of options out there and many are reasonably priced; e.g. area rugs) and experiment. Cover most of the wall surface to begin with and then incrementally reduce the treated area. Leave the first reflection surfaces covered throughout. You may want corner bass traps to complement. At some point, you'll find your best mix.
Good luck.
Marty
To deal with the wall issues, you may wish to follow the process I followed:
Pick up a whole bunch of absorbtive wall treatment (there are a lot of options out there and many are reasonably priced; e.g. area rugs) and experiment. Cover most of the wall surface to begin with and then incrementally reduce the treated area. Leave the first reflection surfaces covered throughout. You may want corner bass traps to complement. At some point, you'll find your best mix.
Good luck.
Marty