How does music "move" down a wire?


Please excuse me for this question if it is dumb. I'm trying to understand how music/sound moves down a wire. (I think) I understand how sound is transmitted through air and that an electrical signal is produced by the source (e.g., stylus in groove) which, after various amplification stages, then 'excites' electrons in the speaker cable.

However, I don't know if different notes (e.g., double bass versus flute) 'excite' the electrons in different ways. That is, do the electrons excited by bass notes move slower than those excited by flute notes? To add complication, music is comprised of many notes played at the same time. Do some electrons move with the bass notes and others with the flute notes, or is it a wave of electrons with various layers of frequency one atop the other?

Would electrons be moving similarly in each wire of a stranded cable (i.e., they would only be excited within the boundaries of that particular wire) as opposed to the electrons moving across the full diameter of the cable?
kencalgary
Thanks Al, very cool logic. Your analysis would of course hold best in scenario of an anechoic chamber. In the average listening room, reflections and nodes etc. would further diminish any vanishing differences in sound imparted by differences in speaker wire length.

I have fretted about this in certain applications in the past and it has cost me in wasted lengths of speaker wire. I haven't ever noticed a difference in sound with differential lengths of wire, but since I was fretting about everything else, I thought I should worry about this too. Apparently not. Thanks again for your analysis.
I have fretted about this in certain applications in the past and it has cost me in wasted lengths of speaker wire. I haven't ever noticed a difference in sound with differential lengths of wire, but since I was fretting about everything else, I thought I should worry about this too. Apparently not. Thanks again for your analysis.
You're welcome! Keep in mind, though, that my comment only addressed the question of arrival time differences.

If other parameters, such as resistance, inductance, capacitance, and possibly skin effect, are not small enough to be negligible in the longer cable (all of those effects are proportional to length) a length disparity could conceivably have audible consequences.

And of course there is also the practical factor of resale value being less if lengths are unequal.

The likelihood of those effects being audible, btw, besides being dependent on the design and length of the cable, is also highly dependent on speaker impedance, and the variations of speaker impedance with frequency. Everything else being equal, higher speaker impedance can be expected to result in smaller cable effects.

Best regards,
-- Al
Please, a follow-up question about signals "moving" through wire. I read that a signal takes the easiest path. If you pair two wires for, say, the positive run - one wire with fine strands, the other with large strands - will that create some difference in signal transfer, no difference, or will it provide more "bandwidth" for all frequencies?
I read that a signal takes the easiest path.
Hi Ken,

That's actually a bit of an oversimplification.

In the case of dc, if two parallel paths are present the current will divide up between the two paths in inverse proportion to the resistance of each path.

In the case of ac, the current will divide up between the two paths in inverse proportion to the impedance of each path, "impedance" at audio frequencies essentially being the combined effects of resistance, inductance, capacitance, and to a slight degree skin effect, at each particular frequency component that is present in the signal.

Paralleling two wires for each leg of the run will have the net effect of reducing overall resistance and inductance, and increasing capacitance. Except in extreme cases, capacitance is usually unimportant in a speaker cable, while resistance and inductance can be important.

Whether two parallel conductors would perform better than, worse than, or the same as a single conductor having the same values for those parameters is IMO probably not technically predictable, and experimental comparisons would probably give results that are both system-dependent and listener-dependent.

Best regards,
-- Al