KEF Audio PSW 1000 Subwoofer "shift 3 speaker" Questions

...shift pot minimises it at 180'. I don't know how old it is-? bought it on ebay a year ago. It started making the noise two months after i bought it. serial bar code is 992071g. I hope there is a ...

...3-wire plug. With the power OFF, reverse the AC plugs one by one of any other components that have a standard 2-prong AC plug that isn't polarized. Each time you reverse a plug, turn on the system ...