Gary,
The Vp non linearity through passive cables in the audio band won’t allow phase correct performance in any cable on this earth. The math, and the test results will confirm this. If you flatten the Vp (and in turn improve the phase) the capacitance and or resistance factors will go through the roof and add a LOT of reactive loading on the amplifier.
Have the cable’s impedance tested through the audio band. Is it ruler flat impedance? No, it won’t be and neither will the phase response be flat with respect to frequency. In passive cable it can’t be. It is a compromise to keep the amp happy yet lower Vp differential with respect to frequency by balancing resistance and capacitance. You can not eliminate it. Even with AIR as a dielectric the Vp drops with frequency. And, as the frequency drops the dielectric is less and less important right where the non-linearity slope is the worst showing that dielectric showman’s ship isn’t going to be a total answer. As a matter of fact, INCREASING the “C” improves PHASE and this requires a WORSE dielectric! It is all stuck in the math.
As far as currents go, absolutely the woofer will consume 4/5 th the power from the amplifier, as it should. The purpose of bi-wire is to remove the bulk of the IM distortion out of the mid frequencies where the ear is most sensitive. Way low and way high the ear loses sensitivity to IM distortion. Removing MOST of the frequency data to the lower, and less audible, spectrum is exactly WHY you bi wire the mid / tweeter separate as fewer frequencies “add” and create beat frequencies that are the hallmark of what IM distortion is. The current level has little to do with it, it is the SPECTRAL frequency content that creates IM, not the current level. Separate the majority of the frequencies where you can hear them, and keep fewer where you can is the trick that makes bi-wire work.
Back EMF into the amp is also important, but is less so with modern amps than it used to be. Bi-wire makes the back EMF travel back to the amp terminals, and then it has to go through the mid/tweeter terminals to reach the speaker. But, the mid / tweeter is a high impedance path to the lower frequency back EMF…so it stays isolated. The mid/tweeter cross-over is an “open” to the woofer section back EMF.
Show me the impedance sweep through the audio band and that will tell you the truth. No one needs to be involved except the physics.
Best,
Galen Gareis