The only place I have to put a turntable right now is sitting it right on top of my subwoofer, would there be any problems with this as far as magnetic fields or anything?

I'm not worried about vibrations because:
A) The sub will never be on while the turntable is spinning, and
B) It's a Paradigm Servo 15 so the cabinet does not vibrate at all.

What I'm worried about is magnetic fields and stuff like that..should I be concerned? Again, it's a Servo 15 so it's sheilded like a MF'er, but I know it's impossible to completely shield a sub 100%.