Does it matter which way RCA cables go?
IT does not matter. Just plug whichever in and see if it works, if it doesn’t plug it in the other way. Color codes on rca jacks is just to help you know which goes where in your mind. There is no difference in cable for yellow red or white.
How do I join RCA cables together?
How do I join RCA cables together? Drop the outer sleeve of the RCA plug over the wire. Hold one wire to the center pin connector, heat them with the soldering iron, and then apply a small bead of solder. Repeat with the second wire and the ring connector.