So with Speaker-Cables indeed many bet's are off. Having already touched on the Second Order Effects, let's look at some of these effects and how to avoid the negative influence of these. The possibly most objectionable second order effect is due to the choice of the conductor. This uses a large number of non individual insulated copper conductors twisted together for each Conductor. The Geometry is the so called figure-8 pattern, also called shotgun configuration.
Multistranded conductors have a problem.
In the real world they do that all time. The skin effect says that with rising AC frequency the electron flow is being pushed more and more to the outer surface of the Conductor. So, the higher the frequency, the more of the signal conduction will happen in the outer layers of the cabel. The conventional cables multistranded conductor will show even more problems, due the non-linear interstrand conduction near the surface, the presence of surface oxidisation and the like. For all it is worth, the Skindepth for a round Copper Conductor at 20 kHz is about equivalent to the Diameter of a 20 AWG Conductor.