The process of tuning Alpine amplifiers differs very little from that of tuning any other mobile amplifier. While some amplifiers require separate crossovers for proper tuning, many of Alpine's amplifiers, including the F250, come with all of the tools necessary for tuning built into the amplifier. Controls for the gain, crossover mode and crossover frequency are all located on the side of the amplifier near the high level and low level speaker inputs.
Turn the gain adjustment knob to its lowest setting.
Insert a CD into the vehicle's source unit and turn the system volume all the way up until the system starts to distort. Adjust the volume so that it is no longer distorting.
Turn the gain adjustment knob on the amplifier until the system starts to distort again. Adjust the gain knob to the point just under distortion. Now the amplifier will not produce a distorted signal regardless of how loud the source unit volume is set.
Slide the crossover mode selector switch to the "LP" position if a subwoofer is connected, to the "HP" position if a tweeter or midrange speaker is connected or to the "Off" position if full-range speakers are connected.
Choose a crossover point by adjusting crossover frequency knob. Turn on the system's volume and select a crossover point according to personal preference.
