Best way to sort out phase is to
1) Make sure levels between speakers are consistent.
2) Make sure T/A is set properly using one of the various methods (tape measure is fine)
3) Make sure there are no obvious phase issues with pairs of speakers (Measure both speakers individually, then together. Any spot where the together speaker responses dips compared to the individual speakers is a phase issue, If they speakers are playing the same level, it should ideally be IIRC 3db louder when combined.)
4) Use measurement techniques that can show you the phase of the speakers (REW with using sweeps can do this or paid programs like smaart or systune can do it with any audio playing)
5) Fix as much as you can, not all can be.