Several threads have praised the Behringer Feedback Destroyer (BFD) DSP1124P for taming peaks in subwoofer response due to listening room modes. Here is another one. My system uses dual SVS 20-39 CS+ subs driven by a Samson 1000. These provided ample bass from the day they were delivered, but I had difficulty calibrating the subs. Despite repeated calibrations, on some music the bass was too pronounced and on other source material bass was too subdued. I often tweaked the bass depending on the material, but was not satisfied with the result. Using a 200 to 20 Hz scan from the Avia DVD, I confirmed two response peaks below eighty hertz of about 10 db each. After reading numerous posts on this forum regarding acoustic treatments and equalizers to improve bass, I ordered the BFD. Set up was made much easier by the helpful advice on this forum as well as at www.snapbug.ws/bfd.htm. While I have not achieved a flat response below 80 Hz in my listening area, the bass sounds much flatter, tighter and integrates better with my other speakers. There is no longer a need to tweak subwoofer response. The result was almost like getting upgraded subwoofers. The BFD is one of the better investments made in my system considering the modest cost ($120 street price).