Phase should almost always be set to zero for all subs. It should only be altered if its beneficial which is usually not the case. I did mention this in the article under Advanced Calibration tips.
Hi,
I noticed my subwoofer and mains are out of phase at 80Hz which is my crossover frequency.
I can get them in phase by inverting the phase or by increasing the distance.
Which is the better solution?
I don't have the tools to measure the effect. Are they necessary or is there an obvious choice here?
I can understand how delay works and how a phase inversion switch can work, but how does the variable phase knob on the subwoofer work? And again, is it better to use it than to adjust delay to get the subwoofer and mains in-phase at the crossover frequency?