Wow. Yeah, that’s pretty bizarre.
Is the STATIC just a pure “Hissing” sound, or is it very random popping, or does it have any kind of pattern to it (like modulating tones, etc.)
What happens if you leave DIgital TV Box as the SOURCE, but DISCONNECT the cable box from the projector and receiver?
If the static changes in ANY WAY AT ALL, then what I’m halfway wondering is if this might be a Grounding-Loop issue. I don’t know in what country you live, but in many places, this would be called an “Earth loop.”
The reason I say this is, because when I was using my Plus in the truck a while back, I’d get rather loud audio “interference.” It wasn’t pure “static,” as it had a tonal quality to it that would vary with engine RPM. It only did this if I was running my LCD panel on battery. If I plugged the power supply in, the interference would disappear COMPLETELY.
Plugging the power supply in completed the ground path, while leaving the adapter DISCONNECTED allows the “ground” of the panel to “Float.” On UNBALANCED connections (like RCA jacks are,) a stable ground is CRITICAL.
Unfortunately, there’s really only one way to test this out: Make sure ALL of the affected components (WDTV, Projector, Receiver) are plugged into the SAME power source (electrical outlet) via a power strip.
Make sure the VIDEO jack of the Live (which I don’t think you’re using presently) is connected to the projector or receiver to prevent the floating shield of that cable from becoming an “Antenna”. You don’t have to USE that connection, but it helps to test it by grounding it. You could even plug it into an unused AUDIO input… it’s just a ground. :)
All of this assures that all the devices are at the same ground potential.
If the problem goes away, you’ll have to isolate where the floating ground is and have it corrected by either an electrician (if it’s in the Mains.)