I recently moved, and installed my home theatre audio system in my new place the same way as I had at my last place. My system consists of Axiom M22's, QS4's, a VP100, a powered subwoofer from another manufacturer, an Onkyo TX-SR605 receiver and Onkyo DVD player.
I noticed that I now have a very annoying buzzing sound coming from my speakers at higher sound levels. It is a higher frequency than 60 hz, but not a high frequency, I suspect it is a harmonic of 60 hz, such as 120 hz or 180 hz, etc. This sound was not present in the system at my old place. I searched the web and ground loops seem to be a big cause of this (especially the cable signal), but I have tried numerous suggestions and nothing has killed the buzzing.
I did notice that the sound is almost non existent when I place the receiver in Direct mode, which employs minimal signal processing. In all other settings, includig Stereo, the sound is present. The sound is also present through the headphone jack. All pieces of gear are plugged into a strip that is plugged into a single outlet. I have tried unplugging all inputs to the receiver, but this did not help. I tried unplugging the television (conventional CRT set), disconnected the cable from the wall, plugged the receiver into a different wall outlet, plugged the powered sub into a different wall outlet, nothing has helped. I don't think the speaker wires are picking up the noise because as I said I can also hear it through the headphone jack. It is possible that something in the processing module has failed, but not likely. I suspect the AC power, but am wondering why the power supply input filtering wouldn't take care of this. I did think to disconnect the receiver and move to a new location, plug it in, and see if the sound disappears using headphones. If it does, that would indicate some type of interference or power issue at the install location. If it is the same, then I would think that would mean something has failed in the receiver.
I love my system, it sounds phenomenal and is a joy to listen to whether it is music, movies, or just watching television with great audio. However, this noise is really bothering me and is seriously detracting from my enjoyment of an otherwise incredible sounding system. I posted this here as I trust the knowledge of the good people at Axiom and hope someone here can help me out. Thanks!
