A graphic equalizer is a high-fidelity audio control that allows the user to see graphically and control individually a number of different frequency bands in a stereophonic system. A typical graphic equalizer consists of several audio filter/amplifiers, each centered at a specific frequency in the audio range. Most graphic equalizers have two identical sets of filter/amplifiers, one for each channel in a stereophonic system.
The gain (volume) controls in most graphic equalizers are slide potentiometers that are adjusted by moving a control button up or down. Gain is increased by sliding the button upwards. The slide potentiometers for each channel are placed side-by-side, with the lowest-frequency unit at the left and the highest-frequency unit at the right. In this way, the positions of the buttons appear to follow a graphical curve that represents the gain as a function of frequency for each channel.
Graphic equalizers are common in middle- and high-end stereophonic sound systems for consumer use. They are found in practically all professional recording studios. Graphic equalizer programs are also available for use in fine-tuning sound in a personal computer.