I use acoustic panels manufactured by a company called Prime acoustic. They make panels, sound baffles, diffusers and many other products all related to acoustic treatment whether it be a theatre, public meeting rooms, restaurants etc etc. My listening room has had its challenges one being the hard concrete plaster wall that is behind my speakers. Having eliminating my audio equipment between the speakers I thought I would have the perfect set up. But much to my chagrin, although imaging was improved I got an almost harsh echo kind of sound. In simpler terms, an overabundance of reflection. To make along story short I purchased qty 4 - 12" x 48" acoustic Broadway Panels. I placed them between my speakers on the wall which is a space of about 6' to 7' with about 6" between the panels. Initially I placed them even closer together but found that the sound had a very closed in sound proof room feel with no reflection at all but eventually moved them to the spacing that I just mentioned to achieve the results that suited me.
Here is the LINK www.primacoustic.com. Hope this helps. I highly recommend them!!!!
Here is the LINK www.primacoustic.com. Hope this helps. I highly recommend them!!!!