I have a 10 year old Sony STR-D1011S receiver and recently the surround has been acting up. I can hear a little crackle of static and then the voices sound like they are underwater. Background music seems to sound fine. When I switch out of surround mode the voices return to normal. It also seems if the unit is off for a while, things are normal again in surround mode. I haven't checked wiring or settings yet, but I don't have enough knowledge to know where to start. Any help would be appreciated.

Thanks!

I would check the wires first, then the speakers. Or whichever of those 2 would be easiest first on your setup, you know what I mean?

After that, it's going to be a receiver issue more than likely, and it's not a bad idea to upgrade a 10 year old receiver that's acting up.