An Equalizer (íkwəlɑ̀yzər) is commonly known as an “Eq,” which is a piece of equipment in the audio chain designed to alter a sound wave’s frequency response. An equalizer (EQ) can be a dedicated piece of hardware in the studio or it can be a piece of software in a digital recording workstation.

The equalizer (EQ) is used to change frequencies in sound recordings for a few different reasons. First, an equalizer (EQ) can be utilized to accentuate certain frequencies, such as boosting the bass response of a track. Second, as some frequencies have a bad habit of cancelling each other leading to a recording sounding “muddy,” equalization can be used to keep certain frequencies from interfering with each other. Finally, equalization can be used to combat unwanted sounds like feedback, echo or unwanted artifacts of the acoustics of the room in which the track was recorded.