Purpose

Does absolute phase matter? (not to be confused with wiring speakers out of phase with each other - see our Stereo Polarity Check).

Absolute phase means the preservation of signal phase all the way from microphone to loudspeaker, so that an instrument that sends a wave of positive pressure towards the audience/microphone is reproduced as a similar "push" from the loudspeaker (and the singer taking a deep breath, by the loudspeaker sucking in! ;-)

The audibility of preserving the absolute phase is a controversy that has rumbled on since the 1970s (an example here). You be the judge with this blind test!