[rhythminmind]

You have to check phase of everything thats not a isolated single source. There isn't a "proper phase" Theres only the phase relative to another source. The phase of miced audio is determined not only by the polarity of the output but more importantly the time the audio hits the mic. example: moving your overheads even a foot will change the phase relationship of the signal. Phase flipping is common place. Making sure gear polarity the same dosen't stop the need.