RCA cables--or patch cables, as they are commonly called--are used extensively in home and car audio applications to connect electronic components. If you need to connect two components and none of your cables are long enough to reach from one to the other, you'll need to extend the cables. You can extend RCA cables quite easily with the use of a simple device.
Plug one end of your first RCA cable into the female to female RCA adaptors. RCA plugs typically have male connectors on both ends, which plug into female connectors, or jacks, on the equipment. There will be two male RCA plugs on the end of the cable. Plug one into each of the female to female RCA adaptors.
Plug one end of the second RCA cable into the other side of the female to female RCA adaptors. You now have one long cable, as the two RCA cables connected together by the adaptors are now combined into one.
Plug your extended RCA cable into your devices as you'd planned.