I put my 25-31PC+ behind the TV, which sits on a stand. The stand has a few side shelves, where old video tapes are stored. I have removed the VHS tapes for the time being. Can they be damaged (erased or degraded) by the sub? The shelves are 2-3 feet away from the driver. The CRT TV shows no sign of distortion, so I am guessing that the stray magnetic field coming from the sub is pretty weak.