Kicker DXA 250.4 250 Watt Full Range 4 Channel Car Audio Amplifier | 43DXA2504 Variable crossover is switchable between a low or high pass filter for customizing various speaker combinations to get the perfect sound Switchable high and low level input works with any system 12 dB variable bass boost, enhances the deep bass you&apos;re listening for Variable input gain control balances the sound with the rest of your system Auto sensing remote turn on eliminates an extra wire from the amp to the radio when using the high level input