Sorry for the long post, but I promise no more after this one.
Ok here’s the deal, I would stop short at saying all wire is equal for speaker use. Because in reality this is not the case. When referring to cable for speakers, I would not recommend cheap lamp cord. I would recommend a good quality cable, for example from a reputable brand manufacturer i.e. Belden, Alcatel…etc. Let me play devils advocate here for a minute to explain something, and understand that this is just one of many potential problems that can exist in cheap lamp cord. I will not even deal with the problems of composition of the copper in these cables.
Cheap cord is just that, cheap; it is for the most part made in China typically, and is manufactured in older mills using archaic technology. For this example I will cite a very common periodic manufacturing problem that happens in cheap cables. Lets say for example XYZ manufacturer in China has a wheel in their extruder which is out of round. This out of round wheel may stretch the center conductor making it microscopically thinner at one point. Or the dielectric might come out slightly smaller in diameter for each turn of the wheel. While such a change is very minor, and may not even be readable with test gear, or noticeable in use, this flaw will be added over and over and over again each time the wheel turns. This simple common flaw now adds the dimension of multiple flaws at the same spacing. If you have a flaw every 100 cm (a common circumference for the extruder wheels), over and over, this distance corresponds to a wavelength of a specific frequency. While a 100 cm flaw creates a major flaw at 3 GHz fundamental frequency, this anomaly will also show up to a lesser extent at every harmonic of 3 GHz. It doesn't take many divisions to get to key frequencies for cable television, digital video, digital audio and similar applications. Also, this problem would not be a factor if the cable were very short, but, with increasing distance, this minor flaw could be a major cause of signal problems, and you can't even tell by looking at the cable if this flaw exists. Now you change the cable to one of these premium brands and all of sudden you have a wonderful signal and magically the whole system sounds better. You would accomplish the same thing with a good quality 12-14 gage wire from a quality manufacturer without spending the hundreds of dollars.
