This happened to me on a few albums I transfered over to cdR. As someone else stated, you do need a plateamp with a rumble filter. As far as damage goes, I would think this excessive repetitive movement can't be a good thing. Call one of the subwoofer manufactures and ask them.
Woofer motion problem.
Whenever I hook up a turntable to my rig, or play a flac file that has been recorded from an analog rig, my woofers flutter in and out dramatically more than with even the most intense digital music. I believe this is like flutter and wow that is extremely low frequencies but not sure. I notice these movements during some of the quieter passages on the LPs. Can anyone explain this and tell me whether it can be prevented?