I just noticed at the Polk Store a "Hum Stopping Ground Loop Isolator" for sale. (model: Jensen VRD-1FF ISO-MAX). My electronics knowledge is very limited but I would like the cleanest sound and picture I can find. Currently using digital cable and internet. I can't seem to find any consumer friendly language to explain exactly what this does. Can anyone explain in low-tech-talk what it should do? Already had the cable guy install a small line amplifier.