There’s nothing like a subwoofer or two for adding major bass kick to any factory sound system. The JBL MS-A5001 is a compact amplifier with 500 watts of power and outputs to connect up to two subwoofers in parallel. It accepts any line-level or speaker-level output, and features onboard setup tools for easy, foolproof installation. A digital input mixer lets you map your inputs to either output, and sophisticated network circuitry puts you in precise control of the crossover points and slopes. Serious bass is an essential element of any great car audio system, and the MS-A5001 delivers it with easy precision.