Equalizers

In audio processing, equalization (or equalisation, EQ) is the process of changing the frequency envelope of a sound. In passing through any channel, temporal/frequency spreading of a signal occurs. Etymologically, it means to correct, or make equal, the frequency response of a signal.There are many kinds of EQ. Each has a different pattern of attenuation or boost. A peeking equalizer raises or lowers a range of frequencies around a central point in a bell shape.In Multitrack recording and sound reinforcement systems, individual channels have equalization for aesthetic reasons, while the combined mix of sound is processed through equalization for practical reasons. Any acoustic space will cause some sound frequencies to be louder than others.This is due to standing waves produced by the size of the room and the materials in it. Equalization is used to compensate for the discrepancies of a room’s acoustics.

All audio records have had equalization applied to the sound waveform before the consumers’ record was made because of the limitations of equipment for recording and manufacturing the record.