CCA is only about 68% as conductive as pure bare copper.
The entire cable assembly is jacketed in a black, CL2-rated PVC material. Even speakers rated for a nominal 8-ohms, may dip to as low as 4-ohms at some frequencies, which further reduces the total cable resistance allowed in the wire. Monoprice Speaker Wire, CL2 Rated, 2-Conductor, 16AWG, 250ft, White Using Pure Bare Copper speaker wire ensures that the total load put on the amplifier remains as close as possible to the impedance curve of your speakers.