I bought some new main speakers a while back. However, on my receiver, there are connections for hooking up a second set of mains. Before buying my new ones, I was using some pretty decent speakers. When I tried hooking them up with my new mains, they weren't proving any sound. Is there something else I need to so on my receiver so this works? I didn't se much about it in the receiver's manual. Has anyone tried this before? How does it sound?