You can place them side by side and use a splitter, or run another sub cable or a wireless adapter. I know a lot of people say placement is key, but Im not sitting on top of a subwoofer or remodeling my house to put it in the best audible location, I put it where the wire is and where the furniture dictates, comfort, aesthetics, and then sound quality for me especially when it comes to home theater...
adam beat me to it