Check absolute phase by disconnecting a speaker and applying current from the positive pole of a 1.5V D-cell battery to the positive speaker terminal. This should cause the speaker cone to extent outward.
Assuming that the channels in an amp that powers the speakers in a multi channel system are in phase and correctly marked this will cause all the speaker cones in the system to move outward when a positive signal from the amplifier is applied to them - and that's absolute phase.
Assuming that the channels in an amp that powers the speakers in a multi channel system are in phase and correctly marked this will cause all the speaker cones in the system to move outward when a positive signal from the amplifier is applied to them - and that's absolute phase.