SSP 800 High pitch noise from back speaker
 

As the title says. I've had the SSP800 for some years now. And its great. But after we moved, one of the backspeakers has had a highpitch noise in it. I suppose it could be something electrical? Or something in the box?

Any pointers or suggestions?

Did you resolve this or is it still happening? Does it happen after you power cycle and let power down fully, the entire system? Have you tried putting another speaker in the same location to determine if the problem goes or way?