Earthquake Sound MB1 MEGA Bass Digital Bass Synthesizer for Car Audio Advanced digital bass restoration system detects the input level from a factory stereo, then adds more bass at high volume levels while keeping your bass response balanced at low volume SWEEP and WIDE controls manage frequency ranges for extremely high precision, custom-built bass response Balanced inputs handle very high signal voltage up to 15 Volts and help minimize feedback Dash-mounted remote control knob Portable music enhancement with woofer protection circuitry