Yes, you can use the component cable for the subwoofer. A component video cable, individually, is available for purchase. In such a case you can find it under the name of subwoofer speaker cable. You can easily find these cables on any product search engine that sells multimedia products. You can also have it backwards in terms of reverse. These cables will always work for analogue audio while an analogue audio cable does not require the same process and many not well for a video.