I had to add a pair of active studio speakers (they have there own internal amplifiers) to a amp+ system running a pair of efficient passive speakers.
I put a line conditioner (like for car audio systems) to drop the voltage of the speaker output from the amp+ to feed the input to the active speakers. I always get a hum from the active speakers but no hum from the passive speakers. The line conditioner has two ground wires that are not being used.
Should these ground wires be connected to the amp+ board? If so where? Is there a way to stop the ground loop hum on the active speakers?