JL Audio XD400/4v2 4-channel car amplifier &mdash; 75 watts RMS x 4 4-channel car amplifier 75 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms) 200 watts RMS x 2 bridged at 4 ohms (4-ohm stable bridged) Class D amplifier design with NextD switching amp technology 8-9/16"W x 2-1/16"H x 7-1/8"D