Hi @krazykyle. It's interesting that you should say that. I have the same speaker set and the same issue.
I started off with a Promedia 2.1 which gave off this high-pitch noise coming directly from the subwoofer when the system was switched off. After a consultation with Klipsch themselves, I sent that set back to Amazon and got a replacement.
The second Promedia 2.1 set (currently in use) has the same issue, but this time when the system is switched ON.
It doesn't happen every time I switch the speakers nor does it happen instantly when I switch them on. I can be listening to music for half an hour and all of the sudden, this high-pitch noise will begin and the only way to get rid of it would be to switch the system off.
I would be interested if a solution to this issue becomes available.
- Thank You.