As an addendum to the information provided by Jcharvet, indeed heavy drapes or rugs will work. However, for my application, I purchased absorption panels from Acoustical Solutions: http://www.acousticalsolutions.com/acoustical-wall-panels.
Additionally, one can either buy purchased complete panels as I, or DIY, by buying Owens Corning 703 panels, fabric, etc. such as available here:
http://www.buyinsulationproductstore.com/servlet/the-492/Owens-Corning-703-Acoustic/Detail
http://www.atsacoustics.com/cat--DIY-Acoustic-Materials--102.html
http://www.acoustimac.com/dmd-acoustic-panel-422/
Websites with DIY acoustic panel information follow:
http://www.facstaff.bucknell.edu/esantane/movies/Acoustic.html
https://sites.google.com/site/computeraudioorg/do-it-yourself
After I mounted apsorptive 2" thick panels in back of my Soundlab ESL's, wow, what a positive difference (huge smile)! They improved the sonics at least, if not more, than any item that I ever bought! Frequency response remained essentially the same, but focus, clarity, imaging and soundstage dramatically improved.
My experience (at least with Soundlabs) suggests that its paramount to absorb the back-wave emanating from the panel and its quite difficult to overly dampen that portion of the listening room.
Before installing acoustic panels, I allowed uncertainty with the science verses the art of acoustics, to inhibit purchasing and installing treatments. However, Roger Wests discussion via Soundlabs set-up tips page http://www.soundlab-speakers.com/#!__technology/setup-tips, and discussions with a local audio store owner whose opinions I respected, convinced me that installing absorptive material is better than not, and if that were so, I needed to do more and as Ive discovered, the end result was a resounding success and highly recommended!
Additionally, one can either buy purchased complete panels as I, or DIY, by buying Owens Corning 703 panels, fabric, etc. such as available here:
http://www.buyinsulationproductstore.com/servlet/the-492/Owens-Corning-703-Acoustic/Detail
http://www.atsacoustics.com/cat--DIY-Acoustic-Materials--102.html
http://www.acoustimac.com/dmd-acoustic-panel-422/
Websites with DIY acoustic panel information follow:
http://www.facstaff.bucknell.edu/esantane/movies/Acoustic.html
https://sites.google.com/site/computeraudioorg/do-it-yourself
After I mounted apsorptive 2" thick panels in back of my Soundlab ESL's, wow, what a positive difference (huge smile)! They improved the sonics at least, if not more, than any item that I ever bought! Frequency response remained essentially the same, but focus, clarity, imaging and soundstage dramatically improved.
My experience (at least with Soundlabs) suggests that its paramount to absorb the back-wave emanating from the panel and its quite difficult to overly dampen that portion of the listening room.
Before installing acoustic panels, I allowed uncertainty with the science verses the art of acoustics, to inhibit purchasing and installing treatments. However, Roger Wests discussion via Soundlabs set-up tips page http://www.soundlab-speakers.com/#!__technology/setup-tips, and discussions with a local audio store owner whose opinions I respected, convinced me that installing absorptive material is better than not, and if that were so, I needed to do more and as Ive discovered, the end result was a resounding success and highly recommended!

