I was listening to Groove Armada down by the riverside today (just on the pc plugged into the amp) and I noticed that at not a very high volume with loudness off and eq off there was a large amount of movement from the bass driver. It happened when there was nothing really playing just a bit of quiet music. It kind of freaked me out so I havn't played the song since. Also when I play Pink Floyd DSOTM on vinyl, the same thing tends to happen. You cannot hear it, but the driver is moving rather confidently in itself! Dodgy recordings doesn't sound right from Floyd, so I can't work out where the fault lies.