Diffuser or absorber behind listening position....and is it worth doing??

As an option to consider, Jeff Hedback is a designer who has created several hundred studios and also a large number of high end personal listening space designs. I've used several of his studio designs myself. Jeff basically works from his home, employs remote techniques to read your room acoustics, and works with you to create a custom design. The design comes to you in the form of architectural drawings and specifics as to materials and techniques. He then monitors the progress and results with more remote measuring methods. Award winning work and a nice guy to talk with. http://www.hdacoustics.net/

https://ua-acoustics.com Way less $ than GIK but not as pretty.

Or buy a 12 pack of  2' x 4' x 2" Owens Corning #703 rigid panels and experiment. $130.

Try 2 front, 2 back and one each side per Eric's instruction.

I don't know if treatments will provide the sound staging improvement you are looking. It will clean up the
"Smearing" effect you get when the same sound is reaching
your ears to close together in time.

In my mind this comes well before any other considerations.

You are at a very great/exciting/rewarding stage of Audiophilia
as the improvements in front of you now will make make the
biggest SQ improvement you are likely to achieve.

Please let us know your results!

Blankets and pillows can be your friend when experimenting.  Cover your TV, and put up a make shift absorber on the sides. 

If you do put something on the sides, again, due to lack of materials, go for a thick panel, but now you should consider diffusion as well. Look at the GIK impression series.  They can come with feet, so you could for instance put a diffusor in front of your TV while listening and move it out of the way when you need to.

Hi @chorus,

 I was just looking at the OC 703 panels yesterday.  How are you using the panels? I   Was thinking of making a frame out of 2x2 and hanging them on the walls.  If they work, I can replace the 2x with nicer frames and my wife can pretty them up.

Thanks

JD

Chorus recommended ua-acoustics for a really cheap solution.  Be aware that these are just foam panels.  They are NOT the same thing as GIK panels which use fiber material similar to Owens 703 and the like.  I have tried foam panels before and they really don't do what you want them to do.  They don't absorb all frequencies and I actually had worse results with foam panels.

GIK Acoustics really is the cheapest "GOOD" solution here.  There is a company called ATS Acoustics that has panels slightly cheaper than GIK, but they use a hard-back panel frame (essentially a 1/4" piece of plywood on the back).  This is not the design you want because I have found the hard-back will resonate with the material and create more echo/vibration.

The 3lb 703 is excellent choice to work with because it is super light and it also does not sag.  I wouldn't recommend the 6lb 703 because it's a lot heavier and doesn't really do much different.  For my room, I just took a 703 2x4 panel and wrapped with with Guilford of Maine black fabric.  I just used spray glue on the back side to hole the fabric closed.  I don't made frames for my panels, but I also don't hang them (I just sit them on the floor/wall or on top of a bass trap agains the wall).  You can make frames if you want.  It's really not difficult.  Just get some light weight pine 1x2 from Home Depot and cut them.  Then glue/nail/screw the frames together and inset the 703 into the middle.  Then wrap with fabric of your choice.