I promise you, it's not. There's a lot of articles floating around recently about the placebo effect in medicine. I'll be kind to these people, and let them off with the excuse that placebo effect, which is still not understood, is the reason their $500 cables make them think their audio sounds better.
Audio is something we understand pretty well. We can measure it's delay and phase and amplitude and distortion. We can measure these things, and we can see when they change, and we can see when they don't change. We can see these changes to levels that the human ear can't detect, but even if you believe that an audiophile can detect things that others can't, we can see these changes on our instruments.
I'm not certain how far to beat this horse. It's a little like arguing that gold doesn't fall faster than lead, even though gold is heavier. At the end of the day, you either believe in measurable science, or you don't. As somebody who has spent countless hours in front of an audio analyzer, tracking down actual audio effects all the way down into the noise floor of the system, I am confident on this issue.
Still, the guys selling those cables are richer than I am, so who's the idiot? Certainly not the salesmen.
Further robotrout's point: a friend of mine did some research on actual sound quality for generic versus high-price cables.
He measured the noise floor with Monster cables at about -160dB, whereas cheap crappy cables were about -125dB. However, he also found that basically all of the difference is explained by higher quality connectors on the Monster cables compared to his ultra cheap bargain basement ones; when he replaced the cheap connectors with some modestly priced RCA connectors that weren't utter shit (but were not Monster cable made), the two cables were indistinguishable.
For the record, even -125dB is below the noise floor of arguably every person on earth.
So really, the most important thing for cables is to always use good connectors. You cannot hear the difference between "super duper copper" and "layman's copper."
Another popular bit of audiophile snake oil is "ribbon cables." These use wide, flat conductors instead of round ones because---they claim---the round conductors have higher impedance because of the skin effect (http://en.wikipedia.org/wiki/Skin_effect ). Of course, this is absolute bullshit, because skin depth at audio frequencies is more than the diameter of the round conductor. What's more, since ribbon cables aren't coaxial, they're actually more susceptible to EMI.
...and people still spend hundreds or even thousands _on_the_cable_!
> It's a little like arguing that gold doesn't fall faster than lead, even though gold is heavier.
is a bad example, because heavier items do fall faster. If the difference in masses between them is very large (like a box vs the earth), the difference is not measurable, but it's there. It's off topic, but if you want me to show you the math I can.
Audio is something we understand pretty well. We can measure it's delay and phase and amplitude and distortion. We can measure these things, and we can see when they change, and we can see when they don't change. We can see these changes to levels that the human ear can't detect, but even if you believe that an audiophile can detect things that others can't, we can see these changes on our instruments.
I'm not certain how far to beat this horse. It's a little like arguing that gold doesn't fall faster than lead, even though gold is heavier. At the end of the day, you either believe in measurable science, or you don't. As somebody who has spent countless hours in front of an audio analyzer, tracking down actual audio effects all the way down into the noise floor of the system, I am confident on this issue.
Still, the guys selling those cables are richer than I am, so who's the idiot? Certainly not the salesmen.