No not the type of buzz when you are 'on someting' however whenever I move my MX700 it creates a sort of buzz in my DTT2500 speakers. The reciever unit is away from the main decoder.
Anything I can do to stop it, as its not loud but just enough to annoy me when I am not playing games or anything. Also it gets louder if one turns the volume up, so its proportional.
Cheers.