The basics of using an equalizer
Equalizers are a very common tool in audio production. In essence they allow us to adjust the tone of an instrument or voice. The most basic equalizers can be found on a home or car stereo, they are commonly known as the bass and treble controls.
Equalizers can be used for correction of the tonal response caused by the recording process or for enhancement. An example of correction could be taming the high frequencies on a vocal recording that was recorded using a very bright sounding microphone. An example of enhancement could be adding some extra bass to a kick drum to make it sound more powerful.