I just recieved my first ever subwoofer yesterday, a SVS PCB12-2 Plus. I went home, did a quick calibration on the sound level, and started watching a few scenes from some movies...not at real loud volumes, about -10 to -15db. After a few minutes, I switched to some concert videos. After 15 more minutes, I got up to switch the disc, and I could not walk...I had no sense of balance and was bumping into things! I know that tests have been done to show effects of sound pressure waves on people, but has something like this ever happened to anyone? I've never experienced that type of nausia before. Maybe it was a freak coinsidence. I will try again this weekend to repeat it. I have not done a frequency scan of my room yet.