The art of optimizing molecular alignment of the cable materials by deep freezing.
The issue of different audio frequencies being transmitted closer and further from the surface (skin) of the wire, and how to avoid / make use of the effect.
General treatise on the effect of interweaving different wire materials (refer to pages on specific variants for specific effects)
The various gauges of wire used and their sound effects.
OFC, OCC, % purity, resistors, etc.