JL Audio M600/1 Mono Subwoofer amplifier, 600 watts RMS x 1 at 2 ohms

JL Audio M600/1 Marine/Automotive monoblock subwoofer amplifier. Delivers 600W RMS x 1 @ 2Ω. The unit is in excellent working order and rates about 9/10 cosmetically, with only a few minor scratches. This amplifier was never used in a marine environment — it lived in a vehicle and powered a JL Audio 13TW5v2 subwoofer with strong, clean output. A similar M600/1 tested by Williston Audio Labs on YouTube produced 669W certified at 2Ω (1% THD) and up to 796W dynamically, which aligns with JL’s reputation for underrating their amplifiers. Despite its power, it has a remarkably compact footprint at only about 8.75" long and 7" wide. Here are the specs, courtesy of Crutchfield Product info: mono marine / automotive amplifier 400 watts RMS x 1 at 4 ohms (600 watts RMS x 1 at 2 ohms) Class-D design white and gray powder-coat finishes, gasketed control cover, and stainless steel hardware variable low-pass filters (50-500 Hz, 12 or 24 dB per octave) subsonic filter (30 Hz) optional remote level control preamp-level inputs preamp outputs 4-gauge power and ground leads recommended — wiring and hardware not included with amplifier 8-1/2"W x 2-1/16"H x 7-1/8"D