📖 Audio Glossary

Phase

The timing relationship between waveforms — in-phase signals reinforce; out-of-phase signals cancel.

Phase is measured in degrees (0–360°). Two identical signals at 0° phase difference sum perfectly (+6 dB). At 180° (completely out of phase), they cancel completely (−∞ dB, silence). At intermediate phase shifts, they partially cancel with a comb-filter effect.

Phase issues arise from: multi-mic recordings (two mics capturing the same source at different distances), stereo widening effects (which manipulate phase to create width), and room acoustics (reflections arriving at different times). The polarity invert (phase flip) switch on interfaces and DAWs flips the signal 180° — useful for checking and correcting phase relationships.

Related Terms

Phase ResponseA graph showing phase shift at different frequencies — linear phase (all frequencies delayed equally) is ideal for preserving transient timing.Comb FilteringAn interference effect creating a series of peaks and dips in frequency response — caused when direct sound combines with a delayed copy.
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