Audio cables make a difference, but they should be the last on your list speaking of your system as a whole. Save yourself a ton of time, money and frustration and know what it is in playback, and the sound, you really want to reach. Get the right loudspeakers for your sense of music and sound, find the happy amp that feeds ‘em; then get busy on your analog and digital source needs. Fill your room with a bunch of albums and books and stuff. And once you have a hi-fi rig you like, start messing with cable. And careful not to use cables as tone controls to fix a loudspeaker or setup issue—it’s a trap that will have you spending more money on accessories than on music. If your system has a timbre problem look at your room, amp, speakers…. Yes, interconnects and loudspeaker cables can make a large contribution, as can power cable though not as often. Each type should be looked at individually.
RCA-type interconnects patch together gear with no power factor, here impedance makes very little difference, at line-level it’s all about preserving the inserted signal without introducing reactive elements—parallel capacitance (Cp) being prime—that cause time and frequency problems. It’s also about protecting the small signal from environmental influences, RF in all its forms and to a much lesser degree vibration. Loudspeaker cables transmit both power and intelligence and are designed very differently, with impedance playing a much larger role. AC power cables.... well that’s a bit tricky. It depends on so many factors that it’s impossible to predict if a hi-fi power cable will even make a difference. The power grid in your area, the transformer feeding your house, the grounding of your home’s grid, the noise on your lines, the ground relations of your gear and on top of that you have the power supply of each component in your playback and the chassis that protect the power supply, circuits and mechanisms. The perfect power supply would not benefit from a super duper power cable. But, since perfection isn’t attainable, and there are audible changes from mains cable swapping, you get the current power cable proliferation that is hi-fi today. Power cables for Zu is about containing the radiated fields and this takes a whole lot of conductor; a simple foil doesn’t cut it. Zu also believes in keeping the ground circuits’ impedance as low as possible. All this is a very brief overview focused on the fundamental reasons for fidelity preservation and electrodynamics. Chemistry and other branches of physics are also used by Zu to research, develop and finally market a good sounding cable, but way too much has been made of “conductor purity” to justify the stupidly high prices charged for cables.