Audio Systems: Home audio speaker squeal, polk audio speakers, cabinet rack

Question
Hello, I recently purchased some new Polk audio speakers 5.1 and have
them hooked to my onkyo 606 av reciever using monster cable xps 16 ga
audio cable. When I listen up close, ear to speaker I hear a distorted
squealing sound, it isn't really noticable while sitting on the couch. I have all
the cable hooked up correctly, and am just using the bare cable to connect,
not banana connectors. Is this normal? Also I have a little static coming
through. All my cables connected to my receiver are shielded. So I'm at a
loss for ideas. I have two hdmi, one component, said speakers and a
velodyne sub via sub cable.  All video goes to tv through a hdmi out.   
Thanks for your time.

Answer
Have you tried disconnecting the input to the receiver? Do you hear the distortion on other sources? Does the distortion let louder when you turn up the volume? Can you hear the distortion when the volume is all the way down (counterclockwise)? Where is the Onkyo situated (cabinet, rack, shelf? What other equipment is near the Onkyo? Are you using any motors near the Onkyo? Is the distortion always there or is it intermittent? Have you tried disconnecting all inputs to the Onkyo and listening for the distortion? Is there a cable or satelite box connected to the Onkyo?

Cables should not be the cause of that problem.