Thanks everyone!
The source is a our office 50" TV w/ Amazon Fire Stick. It also happens when I use the AUX and play music off my iPhone.
The distortion happens with a variety of feeds from Youtube, Netflix, Prime Music, etc.
Yes, I have used the balance knob from the receiver. The sound is reminiscent of a static/scratchy sound. It's not heavy by no means and I can live with it. But it's there, it's more prevalent with higher frequency sounds. The right speaker sounds perfect and yes it happens when I switch the speakers as well. It's quite baffling. I will have to call Sony tomorrow as well.