I'm trying to hook up a new subwoofer using the wiring in my house that was installed when the house was built. The cable for the sub is just a coaxial cable with no ends, so I need to stick an RCA ...

First, yeah I know don't use a TV for a center channel. I know all about it so please don't post if that's all you're going to say. I have a home theatre receiver that outputs to the usual speaker ...