Machine>I still, for the life of me, cannot figure out how an oxygen molecule can interfere with an electron travelling on the exterior of a copper cable.
Mainly because Oxygen is second only to Fluorine in electronegativity (translation: Oxygen really, really likes electrons, and once it has them (from other elements or another oxy atom), it holds them tight). When it forms compounds with (very conductive) Copper or Silver, the normally free ranging electrons are now locked down by the oxide compound. The compound becomes a semi conductor (or worse: an insulator) that the electrons have to go around (or thru).
So....... Oxygen and other atomic "impurities" introduce electrical "breaks" and high resistance areas on the surface (and interior) of the conductor that interrupt the smooth "handoff" of electrons from atom to atom. Net effect is increased electrical resistance.
For speaker cable, resistance is the only thing that counts. It's a balancing act between material, gauge, run length, and acceptable signal attenuation (loss). I scoff at Monster and others as they talk about things like "phase coherance" - pure baloney. I could make wires out of water filled flexible plastic pipe that would be indistinguishable in sound quality (but probably not in appearance) from their "top of the line" cabling. Also, my "wires" could water the grapefruit & avocado plants I've got going. Can theirs?
Xenno