What is Phase Cancellation?
Also called: phase, out of phase
Phase cancellation happens when two similar signals are combined while their waveforms are out of step, so they partly or completely subtract from each other. The result is a thinner, quieter or hollow sound.
If two identical signals are combined with one of them inverted, they cancel completely. In practice, cancellation is usually partial: two microphones at different distances from a drum, or a stereo effect that delays one side slightly, cause some frequencies to drop out while others add up, which is called comb filtering.
The same effect is behind the old trick for removing vocals: subtracting the left channel from the right cancels anything panned dead center. It removes the lead vocal on some songs, but it also removes the kick, bass and anything else in the center, and leaves stereo reverb on the voice behind. That is why modern vocal removers use AI source separation instead.
Flipping polarity, nudging the timing of one track, or checking in mono are the usual ways to find and fix phase problems.
Put it to work
Remove vocals with AI separation instead of phase tricks, and keep the bass and drums intact.
Vocal Remover