PSW350 Problem

[lbnrph]

I have a PSW350 subwoofer that emits a pulsating sound at random times. Everything can be off and it suddenly starts making this sound. The only way to stop it is to unplug it. Any suggestions???

[MxStYlEpOlKmAn]

like a heart thump, it'll go away over time, i have had this happen to one of my subs, just unplug it for a while then replug it, but what the heck do i know? contact polk cs

[STUFFMD]

Any dimmer switches ......dimmer lights in the house????....I had a hum in mine found out that's what the problem was...
Good Luck, Peace StuffMD