If you'll allow a "mature" person whose hearing may not be as good as it was a few decades ago to explain the relevant parameters...

A speaker's impedance varies with frequency; an "8 ohm" or other rating is "nominal", usually taken somewhere in the middle range. In order for a speaker to deliver relatively flat acoustic output, it has to be driven by a source (amplifier) having constant voltage output even if the speaker impedance (and therefore current required from the amp) varies. Decent modern solid-state amps typically have an output impedance under 0.1 ohm, thereby changing output voltage very little with load, and that would solve the problem if only we didn't usually need to have the amp and speakers separated from each other .

So the goal is to limit how much additional resistance gets inserted between the amp and speaker; the more resistance, the more audible the effect of the change in speaker impedance with frequency will be.

From a practical standpoint, if speaker wire resistance doesn't exceed 10% of a speaker's impedance, the audible effects are low, and at 5% or less, mostly unnoticable. One approach is to first determine the speaker impedance (minimum, if the manufacturer gives it, otherwise nominal value). Then divide that impedance by 20 (5%), and further divide by the number of feet between speaker and amp. The result is the maximum resistance-per-foot of the wire that can be used and assure very little or no audible influence from the wire. There are wire tables available online that give the per-foot resistance (remembering that zip cord has two conductors, if the table doesn't take that into account).

Obviously, the longer the wire or the lower the speaker impedance, the heavier the gauge should be to reduce its effect. As to inductance and capacitance, at 20KHz or less standard zip cord doesn't exhibit enough of either to have any significant impact, especially if the wire gauge is otherwise sufficient.

As has been pointed out by others, good tight connections can be as important as wire size/quality. Not only can a bad connection cause power loss and frequency response problems, but corroded metals often form semi-conductors, resulting in distortion and interference due to rectification as well.

Sorry if that got kind of long-winded and technical, but this topic is one of my pet peeves. I hope at least someone found it useful or interesting .


--Barry