Moved to a home with a surround sound system, how do I set it up?
go to Goodwill and get a receiver for like $15. Then hook up the speaker outputs to those speaker connections coming out of your wall in the 5th photo. You dont need to use a multimeter. The speaker wires on the receiver will be marked Left Front, Left Back, Right Front, Right Back, Middle, and Subwoofer. As you hook up the wires, listen and make sure you are connecting to the right terminals.