Dear Bob:
I worked in the music recording industry for a while. The recording studios in the U.K. in the '70s wired their 1-kW amps to the speakers with 30-A, single-strand cooker wire. Sounded okay to me, but a bit loud.
Allan Hurst
via e-mail
Hello, Alan. It's easy to compute that. If you don't mind poor (high) inductance, you can use these big, fat wires. But they're awfully hard to manipulate—bulky, lumpy, stiff, awkward. Plus, low-inductance wires will give less high-frequency phase shift and less skin effect—not that anybody can hear that. If you're going to drive 1000 W into 4-Ω speakers, it would probably make sense to use heavy wires to avoid excessive heating. Hey, 15 A is a lot. I'd guess that 12- or 14-gauge ordinary lamp cord would be less awkward with less attenuation for long wires, compared to 16 or 18 gauge. But just think about this: pick any speaker wires you want, and nobody can hear any difference anyway! Thanks for writing.—RAP
Allan Hurst replies:
Bob, you're right. The wire was fat and cumbersome. But it was installed just like for a cooker—in the plaster of the walls. After all, studios weren't portable installations! I agree with you. I bet nobody could tell the difference between expensive, fancy Litz wire and cooker cable, given that both were fat enough to carry the current without undue loss.
P.S. There was a great fuss at the time about the phase shift introduced by transformers. The firm I worked for, Neve, decided to see if the problem was audible. You could certainly measure significant phase shift through a good audio transformer. So we rigged up a test jig in a posh London studio with soft-switchable amounts of shift at 3, 5, 10 kHz, etc., and ran blind tests with the local "golden ears." The results were entirely random, as we expected. I don't think that people can hear phase shift as such at high frequencies, especially because a full 360° shift at 10 kHz corresponds to moving your head about 1 inch! Most stereo imaging is down to your brain being pretty good at using the difference in time-of-arrival of transients at the two ears, to a lesser extent, amplitude, and much less again, phase (if at all), except at low frequencies when the wavelengths are big enough for coherent cancellations at both ears.
I gave up on the industry after a while, as it was impossible to correlate what the "golden ears" who bought the stuff said they wanted with any sensible engineering—though they generally had engineering managers who were a bit more sensible. I hear that the HiFi trade is now about 100 times worse.
I've been debating the evils of "objectivism" versus "subjectivism" with some guys. Some of the fantasies of the golden-ear guys are quite amusing, except that they start taking themselves seriously.—RAP