OK. So, the distortion you see when the sub kicks in, is definitly a separate problem from the bending.
I *think* I can confidently say that the bending is NOT the subs fault, but an issue with the TV/tube itself. At 10' away, the sub can't magnetically affect the TV. As a test, take a small magnet and bring it close (not too close) to the tube. Notice how the image bends and discolors? Notice when you pull the magnet away it goes back to normal?
Regarding the distortion when the sub "kicks" - This is either a loose connection or cold solder joint in the video path of that particular input. (Either in the cable itself, or on one of the circuit boards)
