Since the sub is not shielded, there may not be much you can do regarding the tv distortion except moving the sub far enough away or purchasing a new tv (lcd, dlp, plasma).

As for the hum, the great folks at Axiom can offer some suggestions. Also, look into the isolators for either the sub or cable. I tried the one for the cable. It helped but the one for the sub eliminated it completely. It's either or as you cannot use both to isolate the hum.

Keep us informed!

Axiom stuff, Denon stuff, & Sony stuff