Polarity inversion can be used in situations where audio signals are out of phase with each other. Many hardware consoles have a phase button, which is actually used to invert polarity.
Logic Pro X doesn’t have a dedicated button for this purpose, but the Gain plugin has a handy “Phase Invert” feature. I’m not quite sure why Apple decided to label it “Phase Invert” instead of “Polarity Invert,” Semantics, I guess.
To invert the polarity of a track…
- Add the Gain plugin to the first Insert FX slot. The Gain plugin can be found under “Utility,”
- Check “Phase Invert”