Hello folks, I recently ordered a new Polk 12" sub which should be arriving tomorrow. I also have a storage bin full of cables all still in the packages that a friend gave me. I have a Monster Standard subwoofer cable with RCA connectors, and a Belkin Pure AV Digital Coax audio cable with what looks exactly like the RCA connectors on the RCA cable.. Can the Coax be used interchangeably with the other sub cable to connect to a subwoofer? What are the specific applications for a digital coax audio cable? What's the benefit to using coax vs a good quality RCA cable? My AVR does have some coax ports, perhaps I should be using that instead.