Some amps include circuitry that allows you to boost the bass output, ranging from a knob or button that provides a set amount of boost, to a built-in parametric equalizer with many possible configurations and adjustments.
If an amp generates a large amount of heat, a cooling fan can regulate the temperature to prevent the amp from overheating.
Useful if you're adding an amp to a factory radio, or don't have enough preamp outputs on your aftermarket receiver. Speaker Level Input Types: Harness, Speaker Terminal, RCA.
