I am also getting this, as it my friend. We both have 5.1 or 7.1 systems. On mine when opening the pilot/co-pilot doors there is VERY loud static type noise that on my setup seems to come from the rear left speaker. Can supply full details if need be. Thanks.

EDIT:

Here's what I recorded. Used my webcam microphone to record so it picks up the noise rather than tries to record it into the video. ONLY comes out of the rear left speaker, that I can tell.

https://www.youtube.com/watch?v=sRwNInT0Tbs