What is EQ?
Also called: equalization, equalizer
EQ (equalization) is adjusting the level of specific frequency ranges in a sound, making some parts brighter, darker, fuller or thinner. An equalizer is the tool that does it.
Common EQ shapes are the bell (or peak), which boosts or cuts around a center frequency; the shelf, which raises or lowers everything above or below a point; and the high pass and low pass filters, which remove content below or above a cutoff. The Q control sets how narrow or wide a bell is.
In a mix, EQ is often used to give each instrument its own space: cutting low rumble from vocals with a high pass filter, taming a harsh resonance with a narrow cut, or reducing the overlap between a kick drum and a bass line. Cutting is often more transparent than boosting.
Looking at a spectrum analyzer or spectrogram can show where the energy is, but the final judgement should be made by ear.
Put it to work
Generate a spectrogram of your track to see which frequencies are crowded or missing.
Generate Spectrogram