For many years, I have been using speaker switchers for my audio system, AB8SS to be exact. I would like to add a pair of speakers at my shed in my back yard. I ran cables out there in conduit a few decades ago and I don't believe I can run more. Specifically, I have 2 un-used runs of RG-6/U that were intended for security cameras, but are no longer used. Can I use those two RG-6 cables to run left and right speakers? The distance is around 200 feet from the amplified source in the basement. How, and what issues could I expect?