There are tweak audio nuts who know what they are talking about and those who live in a la-la land of self-indulgent fantasy. This includes those i I call
Wire Weenies. :Q
The wrong kinds of wire (or bad wire)
can degrade your audio. For example, if the connectors are coated or otherwise make bad contact, if some of the strands are broken or oxidized, or if the wire is just too small a guage for the job, there can be signal degradation. Sometimes, just cleaning your connectors with contact cleaner, alcohol, or even WD-40 (yes, it works), will make a big difference.
In line level cables, like those between an external CD player or tape deck and your central control system, high capacitance can cause a loss of high frequency information.d This is a function of the length of the cable. The longer the cable, the more important this becomes.
One area where wire can make a difference is speaker wire. This is because speakers typically have a very low impedance (nominally around eight ohms), so even a fraction of an ohm can represent a large percentage of the total impedance seen by the power amplifier. Some of the worst Wire Weenies are
Speaker Spooks. Their explanations defy all known laws of electronics, physics and general reality. There are guys who make wire with arrows indicating which end of the cable should be connected to the power amplifier and which should be connected to the speakers. These guys are blowing smoke, inhaling some of it, and getting a great buzz, but they aren't sharing it with us.
The basic rule is that the wire must be of a sufficiently large guage to handle the current. Stranded wire is preferred because it is more flexible and because, at whatever small level it
may apply at audio frequencies, it minimzes "skin effect" which supposedly affects high frequencies.
The longer the wire run, the larger guage the cable should be. 16 ga. is about a minimum for around ten feet of speaker wire. 14 ga. is better. Any measurable impedance in the wire will degrade the bass, but you can get the same results with an appropriate guage of lamp cord.
A great way to minimize wire losses is to keep the length between the power amplifier and the speaker very short. If you have a entral controlling preamp and separate power amps, you can locate the amps close to the speakers, instead of close to the controller.
The entire mentality of audio tweeks is why I design for professional studio use, instead of that market. They are more tuned into sci-fi mystery oil than any science, whatsoever.