Acoustic Damping Behind Speakers?

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.

Grimace,

Problem - It sounds like you're hearing flutter echo at the listening position that is attenuated when you place cushions on the front wall.

Constraints - WAF, cost, minimal visual impact

Possible Solutions - Flutter echos are most easily heard in the >1kHz frequency range which is easily dealt with. To kill a flutter echo you will need to treat one (or both) of the two parallel wall surfaces, which in your case could be the front and/or back wall. I'd also stay away from adding more absorption as you already have plenty with carpeting and lots of stuffed furniture - adding more absorption will move you closer to a dead sounding room and likely something to avoid. So, here are some suggestions that use diffusion or reflection:

(1.) Add texture to the wall's surface to break up the flutter echos with say a shelf with books or assorted nick nacks on it. This option should pass all contraints.

(2.) Add bass traps with a minimum of 4"-6" depth with a 6" air space behind it BUT WITH a hard surface that faces into the room so as to avoid mid/high freq absorption. Place it in the corners where all room modes accummulate. You can take a 1/8" thick piece of plywood and stain it to match the room and curve it to create a polyfuser (or sometimes called a hemi-cylindrical) diffuser. Or take a 16" or 24" diameter Sonotube used for creating concrete posts and cut it in half to make a 180degree arc and stuff the interior with fibreglass. Cover the curved surface with wood veneer that comes with glue on its back side which is easily applied with a hot iron. Stain or polyurethane the wood veneer to match your room's interior and it'll look like art or an architectural column of sorts. Should pass the cost constraint and depending on taste may also pass the WAF and visual test.

(3.) you could use a diffuser like a QRD or Skyline that when finished in nice wood and stained could look like art work and possibly pass the WAF test. While these do offer some low freq absorption they aren't bass traps so if you want the benefits of bass traps similar to the polyfuser idea above then you might consider building a 'bench' beneath and between the 2 front windows and putting fiberglass in garbage bags (to prevent breathing in air born fibres) in its interior and using 1/8" wood to allow low frequencies to pass through it to the fiberglass.

I'd stay away from using plants as a diffuser - while their irregular shape seems like a good way to scatter sound, the thin leaves can only affect tiny wavelengths of very high frequencies so they aren't effective, unless you're a bat! You could stick a plant in front of something else to help hide the thing behind it, but for diffusion plants can't offer effectiveness over a broad enough freq spectrum.

So to sum up, I'd suggest breaking up the wall's flat surface with diffusion (skyline, QRD, hemi-cylindrical) and adding bass traps but with a hard enough surface to avoid more MH/HF absorption. Hope this is of some help . . .