I am currently in the construction phase for my dedicated home theater in my basement. As I live in the Midwest, the basement floor is concrete as are three of the four walls. Based upon the outstanding reviews on the various home theater sites, I had decided to purchase either a SVS 30-39CS or 25-31CS. I listen to 75% movies and 25% music and the SVS seemed the best option to give me high output with control. That is until I read the excellent "Need help with 20-39CS" thread started by Conrad S. After an exhaustive and incredibly informative process of elimination, the culprit behind the poor performance of his SVS was attributed to room acoustics. Specifically, the concrete floor of his room was noted as an issue. I was extremely surprised to find that such a well reviewed sub would fair poorly in what I feel is not that abnormal of a room construction. What I need help on is some perspective if the SVS subs truly have issues with concrete floors and walls? Is this mainly due to the down-firing nature of the sub and its interaction with the concrete floor? Are the other concrete floor success stories out there with SVS? As a note, my second and third choices were the Hsu VTF-2 (also down-firing - same problem?) and the Paradigm 2200. Thanks for the help.