I have Owens-Corning 703 panels on either side of the speakers, plus I have graciously volunteered to "store" the outdoor deck pillows all over the listening room when not in use. Does it make a difference? Not nearly as much as the 703s. Having guests over for listening sessions helps. All those bags of fluid help absorb and diffuse the sound! One friend loves to lie on the floor between the speakers. A tangent, but I love how non-audiophiles have interesting preferences for listening positions.
