Image quality subjective review

Hi guys,
I watched tv series today on netflix and i noticed somthing really annoying.
When there is a black frame on the screen, i can see a a really annoying noise when im close to the screen.
My friend have the ppx 4835 and he said that its picture is better the ppm, and this thing makes me think that maybe its a problem with my unit.
Heres a video for example :