Why does an audiophile grade power cord matter?

From a purely scientific perspective, the in wall 12 or 14ga. Romex is using pvc as a dielectric and is not shielded and the geometry does not reject all EMI and RFI. If you investigate the dielectric properties of cable, the best is air, but oxidation nixes that, next best or realistic best is VH Audio Airlock cables. It uses teflon aka Fluoropolymer (Dupont is now enforcing the trademark name of "teflon") and the dielectric is lower than teflon/ FP. Thus the most ideal dielectric. I auditioned their (VH Audio) new Olos and Trans cables for line level and amplifiers. Sonically the best power cables I have heard. The connectors were silver rhodium Furutech so cable quality, and quality of connectors plus geometry all seem to be key variables. You question of "why the last 6 ft.".....I don't know why a pulsing signal is changed...filtered...shaped or whatever happens. I find most power cords I use or audition make little to no difference. Audition for yourself and if you hear a positive change trust your ears and beware of grand claims. Many expensive power cables are using the same dielectric as a Home Depot extension cord. I use VH Audio Flavor 4 and LAT teflon 10 awg teflon/FP and they seem to be effective. I use also the VH Audio new Airlock on my Quickies hardwired as bulk wire was cheaper. I had Home Depot wire previously hardwired on the Quickies and yes the sound improved subjectively. Spend carefully. Trust your ears and audition first. Jallen

Well, personally, I don't hear a difference between a mega buck power cord from the stocked cord that comes with the equipment so I just stay with the stocked cords. But I might be in the minority. As one of my audiophile friends told me: if you can't hear the difference, your system isn't high end.

I am sure you can find a lot of posts telling you why a audiophile cord is better. They might be all true but how that affect sound is subjective. Some people can hear it, some cannot. If you are interested in a particular cord, I suggest you borrow one first. Only you can tell if there is a difference and if its price is worthwhile.

I hear the difference I just haven't heard an improvement. I had 2 pair of Quicksilver monos. One had the original power cord which was the equivalent of lamp cord and nonpolarized the other had an IEC socket installed with an "audiophile approved" power cord. Guess which amplifiers sounded better. The amplifiers with the original cord sounded better. I have also tried numerous after market power cords with varied results in several systems. If there is something wrong with the sound of your system and you need to smooth something over or brighten something up you might be able to do it with an after market power cord. I prefer finding the problem.

Eliz....I've heard the same thing before...and to THESE ears, the right power cord makes the most positive difference.