Equalization

Equalization, or EQ, is the shaping of an audio signal's frequency balance by boosting or cutting specific bands, from deep lows through mids to crisp highs. It is the most-used tool in any mix. In dialogue work an editor rolls off rumble below the voice, cuts boxy mids, and adds gentle presence so speech sits clearly. EQ also fixes problems, like notching out a resonant hum or a harsh ring, and carves space so music and effects do not mask the voice. Mixers use surgical narrow cuts to remove offending frequencies and broad gentle boosts to add character. The guiding principle is usually subtractive: removing what is wrong before adding what is missing, since cutting tends to sound more natural than piling on boosts that can make a track harsh or thin.