Hello i have a Polk Audio PSW-10 subwoofer that hums and will not shut off unless i unplug from the outlet.The hum is very loud....Help....Thanks
If the sub has a loud hum coming from the speaker with nothing plugged in, then the switching power supply has failed. If the sub is out of warranty then this sub amp is done.
Your options are slim. That is $100 dollar sub. So a replacement amp will likely cost more than the sub. If you retrofit a better amp it is probably not worth it.
So the recycling center is probably the most appropriate destination for this unit.
I would replace it with a much higher quality unit. Units of this nature are a major problem and a major source of unnecessary pollution. We absolutely need quality and reliability standards going forward. There is no way you can produce a sub of any quality at all at that price and should not even try.