Minimum phase response means that the envelope of frequencies arrives at the ear at the same time and in phase.
To do this we use first-octave crossovers (phase linear) and wire all drivers electrically in phase. Phase plugs in the woofers move their acoustic center forward to the blunt tip of the phase plug, and into the same plane as the mid and treble ribbons. Since these are planar they do not need to be moved back relative to the woofer’s acoustic center.
There are “time aligned” speakers that wire midranges electrically of inverted polarity relative to the woofer and tweeter, which results in measurable better amplitude response. Of course it also destroys the integrity of the music signal outside the crossover region. Phase changes 180 degrees as the signal exits crossover and into the passband, a highly deleterious and audible effect.
