Which type of cable?
Are you asking about speaker cable or line-level interconnects with RCA plugs at the ends? If by chance you are talking about line-level stuff, then I'll share one experience. When the outer part of the plug, which is electrically connected to the shield of the cable, is plated with gold, you expect that it is electro-plated onto high-tensile spring steel. But you can't really be sure unles you take a small pair of pliers and try to bend the outer connector. If it breaks or seems soft, it is made of plastic or cheap pot metal and in the case of plastic, the gold plating is actually paint. If it is difficult to bend but gives and then doesn't return to its orginal shape, it is probably metal and may be electroplated, but it is still inferior to quality steel that has been electroplated. I had several of those cables from Radio Shack, the more expensive ones with the fat rubbery cables and the large plugs that look well made, and used them in a car application, which required some re-work a few years later. After pulling and pushing them a few times, some of the sections of the outer conductors broke away, revealing that the connectors were made of inferior metal.
