Select an audio channel from the mixing console. Mixers number the channels according to the number of inputs provided. For this tutorial, plug your first audio source into "Channel 1."
Match the type of input connector with the source. Audio inputs are normally located on the rear of the console. Many mixers offer both three-pin XLR or one-quarter inch headphone connections for each channel.
Plug in a pair of stereo headphones into the headphone jack of the mixer. Put on the headphones to monitor your audio output from the mixer.
Assign the channel to an output if necessary. Larger mixers may include multiple outputs for both recording and public address applications. Each channel may include an assignment button that corresponds with a specific output. Push the desired buttons to send the channel to one or more outputs of the mixer.
Adjust the slider controls (or volume knobs, depending on the mixer design) found at the bottom of the channel towards the front of the mixing console. Adjust the volume for Channel 1 by moving the slider or knob to its center position. If the volume controls are labeled according to decibels (dB), place the volume control to the “0” position. Do the same for the output volume control of the mixer. The output volume may be labeled “Main” or “Master.”
Test the level of the audio source and adjust the gain. Depending on the equipment used, the signal created by the musical instrument or microphone may be too loud or soft for the mixer. Mixers include a “Gain” knob normally found near the top of the console channel toward the rear of the mixer. Turn the gain knob up or down until the sound of the audio source is either loud enough or no longer distorts the sound.
Apply equalization using the equalization controls of the channel. Most mixers include the ability to adjust portions of the sound spectrum from high to low sounds using a process known as “equalization.” Depending on your mixer, these controls may be as simple as treble and bass knobs or sophisticated equalization that can adjust the levels for a specific range of frequencies.
Locate the audio source in the stereo spectrum using the “Pan” knob. For example, if you turn the pan knob all the way to the left, the sound from that channel will be heard only out of the left speaker. Adjust the pan control until the sound from the channel is located as desired between the left and right speakers.