Though I do think that cables can make a small difference, I don't think they are worth obsessing about. IMO, it is not worth spending thousands on cable when you can spend a hundred or two for something that sounds almost as good at worst. Your money is much better spent elsewhere in the system. Paul Klipsch famously suggested using lamp cord with his speakers. I agree on the whole with Robert Harley's guideline of spending no more than 5% of the total system budget on wire and cable, and IMO, the larger the budget, the smaller the percentage should be. Harley also suggests buying wire in the lower end of the price range of a reputable maker, which is what I did. I am thinking of trying something cheaper eventually. I have heard good things about those Anti-cables, for instance, though I have no experience with them.
As for hearing the differences, a couple of things need to be kept in mind. Many times there won't be any significant difference in quality between one brand and another. More importantly, though anytime you switch a cable out, this has a sort of "self cleaning" effect as far as the electrical connections, resulting in temporarily better sound. The important thing is to keep your contact connections clean. I use a contact cleaner at least every six months, and the result is quite audible. For me, this is the biggest difference one can make with the electrical side of things - IME it makes a much bigger and more positive difference than a power conditioner, etc.
There are certainly a whole lot of folks on this and other boards that will disagree, though, so all you can do in the end is trust in your own ears.
As for hearing the differences, a couple of things need to be kept in mind. Many times there won't be any significant difference in quality between one brand and another. More importantly, though anytime you switch a cable out, this has a sort of "self cleaning" effect as far as the electrical connections, resulting in temporarily better sound. The important thing is to keep your contact connections clean. I use a contact cleaner at least every six months, and the result is quite audible. For me, this is the biggest difference one can make with the electrical side of things - IME it makes a much bigger and more positive difference than a power conditioner, etc.
There are certainly a whole lot of folks on this and other boards that will disagree, though, so all you can do in the end is trust in your own ears.