Connect sound sources to the input jacks of each mixer channel with the appropriate cables. Connect microphones with XLR cables. Connect your instrument amplifier's "line out" jack to a direct injection (DI) box with an instrument cable. Connect the DI box to the mixer input with an XLR cable. Run a microphone from the amplifier speaker to a mixer input if your amplifier lacks a line out jack. Connect a recorded sound source, such as a CD or MP3 player, to the mixer with instrument cables and appropriate audio plug adapters.
Set the master volume level of your mixer and the individual channel gain (volume) settings to zero. Set the individual channel faders to zero. Connect your headphones or monitor speakers to the appropriate output jack of your mixer and power it up. Bring your mixer's master volume up to 25 to 30 percent
Ask talent to perform at the normal loudness while you adjust that channel's gain (input volume) setting. Press the channel's "Solo/PPL" button to send that channel's signal to the audio meter, a row of green, yellow and red LEDs. Increase channel volume until the green LEDs are mostly lit, with an occasional yellow one lighting. Reduce the volume if any red LEDs light.
Adjust bass, midrange and treble tone controls to clarify muddiness, eliminate harshness and increase clarity in the sound output. Readjust the channel gain settings if necessary after adjusting the tone (EQ) controls. Repeat Steps 3 and 4 for each channel.
Ask all performers to perform at normal volume levels and engage any other auxiliary sound sources. Adjust the faders of each channel to balance overall volume differences so each performer and instrument can be heard clearly. Adjust the overall master volume such that the LED output meter stays mostly in the green, with a few yellow LEDs lighting.
Connect the output of your audio mixer to the input of a recording device, using the appropriate cables and adapters. To connect a mixer to a computer for recording, use an instrument cable with a 1/4-inch phone plug on the mixer end and a 1/8 inch (mini) phone plug on the computer end. Follow the recording device or software's instructions and record the audio output from the mixer.