Acoustic Damping Behind Speakers?

The Acousticmac panels work very well for me. I use to bass versions behind the speakers and two "midrange", light thinner panels for side reflections. They also appear to be a bargain compared with others I have seen. I recommend them.

You can use a large thick backdrop (fabric).
They are heavy, that is why they are great at reducing virtually all tendencies of flutter echo and bass mumble.
You can use a wire and tension (device), torque this hard to hold the backdrop. They are avaible in many colours. It takes no space from floor, since it's close to wall and hang like an ordinary curtain.

addition to above post, you can use GIK Acoustics 242 or 244 (on stands or wall mounted) also. 244 reduce more bass/ lower mid, than 242, since it's thicker.

How about a couple large plants (artificial?) as diffusion? It works behind my panels.

I still listen to Supertramp's Crime of the Century.....and am probably down to no more than 20 active brain cells.

I have some of the same issues in my room and am strongly considering some of Furutech's panels. I would like the Acoustic Revive panels also but they are too expensive and sure seem identical to Furutech's. I have tried many of their products and they all have been impressive so I am guessing the panels are the real deal. They certainly get impressive remarks in the press/forums.

My first introduction to high end was a guy down the block who use to sell weed in the late 70's early 80's. He had an array of Phase Linear, SAE and the like and Magnapan Tympani's. We would sit in his basement for hours and hours and Crime of the Century was a go to record. That experience led to my obsession that has evolved into audio insanity. I guess it could have been the chemicals too.