Directionality of Loudspeaker Cables
turnbowm74 Wire directionality is unimportant in an alternating current (AC) application. >>>>It’s nice to hear from somebody who believes there is such a thing as wire directionality at all. By the way, almost all - if not all - audio cables and fuses are in AC circuits, in case anyone is not sure. We’ve already been through why wire is directional in an AC circuit a bunch of times so I’ll spare you the lecture. Consider this exhibit A -All or almost all audiophile fuses sold in the past fifteen years are for AC circuits. And they’re directional. Even the stock cheap fuses are directional. Saying they’re not is just repeating an old wives tale. |
The distinction you (the OP) appear to be drawing between "positive current" being sent to the speaker via one conductor, and electrons being returned to the amplifier via the other conductor, is not correct. During half-cycles of the AC waveform in which the voltage applied by the amplifier on its + output terminal is positive with respect to its - output terminal electrons in the + conductor of the cable move **very** slowly in the direction toward the amp’s + terminal, while an equal number of other electrons in the - conductor of the cable move **very** slowly toward the speaker. (Many electrons in both conductors also move in random directions at all times, but the movements I am referring to that occur in response to the voltage applied by the amplifier can be thought of as a **net** movement of electrons). During the next half-cycle, when the voltage applied by the amplifier on its + output terminal is negative with respect to its - output terminal electrons in the two conductors move **very** slowly in the opposite of those directions, on a net basis. Therefore individual electrons don’t go from one end of the cable to the other. They just move back and forth over a very small distance in response to the AC voltage applied by the amp. Meanwhile, energy and power corresponding to the signal is conveyed in the form of an electromagnetic wave which moves from the amplifier to the speakers at near light speed, usually somewhere between 50% and 98% or so of the speed of light in a vacuum. The very fast propagation of that electromagnetic wave and the very slow back and forth movement of electrons in both conductors are intimately related, and neither would exist without the other in the case of signals being conducted via wires. Most of the energy and power being conveyed by the electromagnetic wave propagates through the dielectric material which surrounds and separates the two conductors, i.e., the insulation. That is why the specific velocity at which a signal propagates in a given cable type, within that range of 50% to 98% or so of the speed of light in a vacuum, depends on the "dielectric constant" aka "relative permittivity" of the particular insulation. A very small fraction of the electromagnetic wave propagates into the conductors, though, corresponding to the fraction of its energy and power that is absorbed by the resistance of the conductors. Power being energy per unit time. Hope that clarifies more than it confuses :-) Regards, -- Al |
Hrrrrrmmmm...Thanks so much for your responses, especially your deep dive, Al. In the late 90's, a friend was designing ic, speaker and power cables that competed with the expensive cables of the day. I would R&D with him in a fine system that included Audio Matiere electronics and some heavily modded, revealing Koss electrostats. He came to trust my ear and feedback and commonly sent me home with cables. Frankly, I don't recall testing directionality since each of his products were clearly marked. All my speaker cables were single wrapped pairs, however, I do recall testing my old 2 PAIRS of Tara Lab Phase II cables with the pairs on the ground pointing back towards the amplifier. I recall it being marginally better and left it at that. Rick claimed that the extruding process left cables directional, sounding better one direction. I'll end with a question. Are all loudspeaker cables sold today marked directionally, and if so, why? Thanks again, Pin |
"....We’ve already been through why wire is directional in an AC circuit a bunch of times so I’ll spare you the lecture." No need for the lecture, but if you could provide a reference/link that would be appreciated. "....Even the stock cheap fuses are directional. Saying they’re not is just repeating an old wives tale." Same for saying that they ARE directional.... |
@pinthrift I'll end with a question. Are all loudspeaker cables sold today marked directionally, and if so, why? Thanks again, PinMany cables sold today are marked directionally, mainly for two reasons: a) because (purportedly) cables become directional through the production process and /or their use (i.e. flow of current) and the marked direction is an easy reference for the user; b) because the shielding, when present, is connected on one end only, and that determines the directionality. |
