@Humpleupagus @charlie_root @ned Phase is really important the lower you go. It doesn't really cause problems most of the time above 500 Hz. That's why so many EDM producers just duck the bass around the kick or at least filter out the lows in the bass (though that's a phase issue in itself). Oscilloscopes are so useful for understanding that. You can just alter the phase of things by putting an allpass at the frequency causing problems.