Yep. When the speakers are in phase, it sounds like the test signal is "in the middle" of whatever speakers you are checking. When the speakers are out of phase, it sounds as if the test signals are out beyond the speakers with a "hole in the middle".

Normally the test starts by checking that your mains are in phase, then tests other speakers against the mains, then confirms with a few other combinations like "just surrounds".


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8