I forgot to mention a couple of things:
When a driver is being run full-range with no crossover or Zobel, its changing impedance curve has no effect on its tone balance when using solid-state amps, but only on tube amps via interaction with their much higher output impedances. For a tube amp running a 'full range' driver, a voice-coil Zobel circuit on that driver would return its tone balance to 'factory spec'.
When a speaker has a flat impedance curve, that does not indicate if this speaker is time-coherent. From the outside, all we can see is how the many different impedance curves I described above combine into one curve.
Best,
Roy
When a driver is being run full-range with no crossover or Zobel, its changing impedance curve has no effect on its tone balance when using solid-state amps, but only on tube amps via interaction with their much higher output impedances. For a tube amp running a 'full range' driver, a voice-coil Zobel circuit on that driver would return its tone balance to 'factory spec'.
When a speaker has a flat impedance curve, that does not indicate if this speaker is time-coherent. From the outside, all we can see is how the many different impedance curves I described above combine into one curve.
Best,
Roy

