Equalointi

Equalointi, or equalization, is the process of adjusting the relative amplitudes of different frequency components in an audio signal to achieve a desired tonal balance or to compensate for the frequency response of equipment or room acoustics. It is a common operation in recording, mixing, mastering, and live sound, as well as in broadcast and consumer audio devices.

Common forms of equalization include graphic equalizers, which provide a fixed set of frequency bands with individual gain controls, and parametric equalizers, which allow independent adjustment of center frequency, gain, and bandwidth (Q) for each band. Shelving filters boost or cut frequencies below or above a chosen cutoff, while notch and peak filters target specific frequencies. Equalizers may be implemented as analog circuits or in digital signal processing.

Technical parameters include center frequency, gain (in decibels), and bandwidth or Q. The phase response of many equalizers is not linear, which can affect transients; linear-phase digital equalizers exist but may introduce latency. Practical use emphasizes modest adjustments, avoiding over-equalization, and verifying results with reference material and proper measurement tools.

Applications span music production, film and TV post-production, theater and live venues, car and consumer audio, and room correction systems. In each case the goal is to tailor the spectral balance to the listening context or to compensate for undesired resonances and system limitations.