I am not familiar with what Rogers and/or Boxee is that you keep referring, but when I had a hum like this I was able to stop it two ways.
1) Unplug the coax feed from my wall to the direct tv box. Also, if I cut back the outer part of the coax, and lifted the ground cutting back and exposing about an inch of only the wire, the sound would.
2) Placing a cheater plug on my sub to the outlet was another way to elimate the noise.
Right now I use the cheater plug for my 350 subs. The 600 stopped humming as soon as I removed the included ground screw.
