If they are they RCAs with the separate set of internal wires then it gets very difficult. I tried that once because I had four sets of RCAS that wouldn't reach the back of my car, and I needed two. So I crimped them together. They kept cutting out and sounded really distant. In other words, I wouldn't recommend it. You will always get better sound from intact cables. New ones range from about $20 to $100 each, depending on the quality, but the quality of even the lower-end new ones will be better than cut-and-crimped ones.