Power and control that's what you get with Alpine's MRD-M501 mono bass amp. And with 275 watts RMS at 4 ohms and Bass Engine digital controls for razor-fine adjustments, outstanding sound is the result. Crank it up, then flip open the top-mount control center and tune your bass to perfection.The MRD-M501 amplifier includes a built-in digital signal processor for the Bass Engine features, giving you a level of fine-tuning capability previously found only in Alpine receivers. Set the cut-off point for the subsonic filter from 15-50 Hz in 5 Hz steps to remove inaudible, energy-wasting low frequencies. The digital parametric EQ allows you to control the width and center point of the equalization curve to improve overall sound.Need more bass The Bass Compensator uses Alpine's MediaXpander found in their receivers to optimize playback of compressed media files to enhance low-end definition of the amplifier's output. Go hands-on with the optional RUX-4180 dash-mount level control knob.The MRD-M501 has a set of preamp outputs for easily getting signal to another amplifier for additional power. The extra-large gold-plated wiring terminals will let your bass really hit, since larger-sized power and speaker wires let the power move more efficiently into and out of the amp.