Connect an audio source to the equalizer. The equalizer must be integrated into the signal chain between the source sound and the recipient unit. If you are equalizing a microphone, connect an XLR cable to the bottom of the microphone, and plug the other end of the cable into the XLR socket on the equalizer, which is a circular, three-pin socket typically situated on the back panel. If you are connecting a guitar to an equalizer pedal, use a standard 1/4-inch instrument jack.
Route the equalizer to the recipient unit, which typically is either a mixing console for recording or an amplifier for broadcast.Connect a suitable cable to the output jack on the rear of the equalizer to the input jack on the mixer or amp. The make and model of the recipient device determines the type of cable required, but it usually is a 1/4-inch jack cable, phono cable or RCA cable.
Normalize the parameters. Move each slider dial to the center or set each dial to "12 o'clock" position. Graphic equalizers have between 10 and 20 slider dials, depending on the complexity of the unit. The dials boost or dip the gain of their respective frequency band. The lowest band is located farthest left, and each subsequent slider governs a higher band. The bands are organized into hertz. For example, the 32Hz band is farthest left, and 16KHz is located farthest right. Setting each dial to the center provides a neutral starting point.
Tweak each frequency band. If you are using an integrated stereo equalizer, play a CD. For vocal tweaks, sing into the microphone, or if you are equalizing a guitar signal, play the guitar. Start with the lowest frequency band and gradually increase and then decrease the frequency by moving the slider or turning the dial. If the sound improves when you boost the frequency, continue to boost it. Once you find a "sweet spot" for the frequency that complements the source sound, move on to the next dial and repeat.