Passive equalizers
One of the most important signal processing devices used in the multi track studio is the frequency equalizer. This devise gives the engineer control over the harmonic balance, or timbre, of instruments herd by the listener and can be used to compensate somewhat for deficiencies in microphone frequency response or for deficiencies in the sound of an instrument.
The frequency equalizer has several uses: to make the sounds from several microphones or several tape tracks blend better than they would otherwise, to match the sound of an over dubbed instrument to the same instrument recorded with a different microphone or in a different place, to make an instrument sound completely different from the way it normally does for a particular effect, and to increase the separation between instruments by rolling off the leakage frequencies.
