First I'm going to have a barn-raising. I don't need a rabbit warren of rooms in my home. Just a lot of space, and I think a barn with a loft would be perfect.
Of course, all that open area will provide plenty of space for a properly configured projection system and speakers ahoy. Whereas...
I have the exact same problem with a Definitive sub. The thing just hums fairly loudly with nothing plugged into it. Connecting it via RCA cable to the receiver has no effect. Both the sub and receiver's power are coming from a Panamax power filter.