Loudspeaker produce electricity you are moving a coil in a mag field thus producing AC. Your sub amp sence this as signal so power up.Amps are fine but seems you have a ground loop problem have you tried a cheater plug to remove ground on sub amp power cords?
Problem with sub amp?
I have Tyler Acoustic PD80s with the built in subs/amps. A couple weeks ago after shutting the system down, the subs in the right speaker started humming. I powered up the McIntosh, the hum stopped, I powered down the Mc and 5 seconds later the speaker started humming again. I run single wire to the lower terminals on the speaker then jump from the upper terminals to the high level input on the PDs amp. When the subs hum I can not detect any noise comming from the mids or horns. The problem happens probably 50% of the time. My fear is leaving for work having forgotten to kill the power, that low hum would drive my dog completely insane after 8-10 hours. I suspect it is a problem with the sub amps... any ideas on how to narrow it down?
Thanks
Thanks