Check the archives using the key words “acoustic panels” and you will find advise, and many "do's" and "don'ts" in treating a listening room. For instance, I would not place absorption panels directly behind speakers; you want the speaker cabinet resonances to reflect freely back toward the wall.
If needed, treatment is used toward the middle of the wall to prevent standing waves from reflecting back toward the listener. Also, if needed, treatment is used in corners behind speakers (bass traps).
You are correct that absorption panels behind the listening position can help reduce extraneous mid to high frequencies.
Most people make the mistake of over-dampening their room on the first try.
Here's some good reading...
http://www.gikacoustics.com/acoustic-advice/
If needed, treatment is used toward the middle of the wall to prevent standing waves from reflecting back toward the listener. Also, if needed, treatment is used in corners behind speakers (bass traps).
You are correct that absorption panels behind the listening position can help reduce extraneous mid to high frequencies.
Most people make the mistake of over-dampening their room on the first try.
Here's some good reading...
http://www.gikacoustics.com/acoustic-advice/