Yup, that's a ground loop. They are pesky buggers. If you want you can try a 3-2 prong adapter on the sub with the sat box and computer connected to see if that gets rid of the hum so you can temporarily enjoy your system while you are in the process of fixing the ground loop properly.


I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne