Chris, note that the resistance of the speaker wire in series with the resistance of the speaker voice coil constitutes a voltage divider. So, excessive resistance(relative to speaker impedance)in the speaker wire when feeding a speaker having varying impedances across the frequency spectrum would result in the speaker response tending to follow the impedance high and low points. This is the basis for the wire gauge suggestions made in Mr. Russell's frequently cited
article , although he doesn't bother to explain the voltage dividing basis for the frequency deviations.
