STEP 10. Setting up the amplifier. Before you mount the amplifier, you want to get set the settings because it may not be easily assessable once installed. Make sure the volume on your audio device is turned down, then Plug the 3.5mm male end of the Volume Control into the headphone jack or audio output jack of your device. Turn on the Key, this will power up the amplifier Turn on your audio device, and push play, turn you can adjust the volume on your device and use the in-line volume control.

To adjust the Sensitivity/gain  setting on the amplifier, turn the amplifier Sensitivity knob all the way down (counterclockwise). Next turn the source unit volume up to almost full volume (usually about 75-90% of the way up). Next, increase the level setting on the amplifier until adequate volume is achieved, or until distortion is audible and then turn it down a bit until the distortion is inaudible.
NOTE-  Ideal signal to noise and dynamic range are achieved with the sensitivity/gain at minimum. Most users find this achieved at less than halfway in the adjustment range. Avoid setting the amplifier gain very high as noise and distortion will increase significantly.

The HP or LP crossover will need to be set to FLAT
Placing the x-over switch in the Flat position all frequencies to pass to the speakers. Placing the switch in the HP or the LP position activates the 12dB crossover, adjustable from 40Hz-400Hz. If you choose to use the HP or LP setting further instructions are available in the Cerwin Vega instruction booklet.

Turn on mode will need to be set to REM