Speaker wires are selected based on quality of construction, price, aesthetic purpose, and convenience. Stranded wire is more flexible than solid wire, and is suitable for movable equipment. For a wire that will be exposed rather than run within walls, under floor coverings, or behind moldings (such as in a home), appearance may be a subjective benefit, but it is irrelevant to electrical characteristics. Better purification of oxidizing materials such as copper is said to result in more consistent conductive properties throughout the length of the wire, but this is a non-issue in terms of its effects on sound quality. Better jacketing may be thicker or tougher, less chemically reactive with the conductor, less likely to tangle and easier to pull through a group of other wires, or may incorporate a number of shielding techniques for non-domestic uses.
Even with poor-quality wire, an audible degradation of sound may not exist. Many supposedly audible differences in speaker wire can be attributed to listener bias or the placebo effect. Listener bias is enhanced in no small part by the popular manufacturers' practice of making claims about their products either with no valid engineering or scientific basis, or of no real-world significance. Many manufacturers catering to audiophiles (as well as those supplying less expensive retail markets) also make unmeasurable, if poetic, claims about their wire sounding open, dynamic, or smooth. To justify these claims, many cite electrical properties such as skin effect, characteristic impedance of the cable, or resonance, which are generally little understood by consumers. None of these has any measurable effect at audio frequencies, though each matters at radio frequencies.