Microphone cable for subwoofer?
I want to connect my subwoofer (energy 12.3) to my receiver (yamaha rx-v775), and searching for a cable, the guy from the shop sold me an amphenol for microphone and two RCA plugs (amphenol too), saying that is the best for the matter. He told to connect the shielding of the cable in the ground of the connector and the two small copper wires to the center of the RCA. Is all of this correct? Do this cable actually works for this, and is this the correct way to build it (shielding to ground, copper wires to center line)?
It looks weird to use shielding as ground, besides, the copper seems too thin.
Thanks in advance!