The G1800.4D is a 4-channel car amplifier from the DS18 G series, built as a Class D design. It delivers 2 x 430 watts RMS at 4 ohms, 4 x 230 watts RMS at 2 ohms and 4 x 150 watts RMS at 4 ohms. The channels are bridgeable, so you can combine them to drive a subwoofer or a pair of higher-power speakers from the same amplifier. Total harmonic distortion is rated at 0.01% with a signal-to-noise ratio of greater than 90dB. A selectable LPF/FLAT/HPF crossover covers 50Hz-4KHz, so you can send each channel only the frequencies it should reproduce. Bass boost is adjustable from N/A centered between N/A. Match the amplifier to the RMS rating of your speakers or subwoofers and set the gain to that rating for clean, reliable output. | Ds18 Audio | | GEN-X 4-Channel Class D Car Amplifier, 4 x 150W RMS at 4 Ohm | Black | Best Buy