MRDF-3

It's rated 400W Dyno-Certified RMS: 100W x 4 at 2 ohms, 60W x 4 at 4 ohms, or 200W x 2 bridged at 4 ohms. That's enough clean power for four marine speakers to stay clear over engine and wind noise at cruising speed.

Yes. Bridge two channels for 200W into a 4 ohm subwoofer, or bridge both pairs to run two subs. Set the crossover to low pass (50Hz to 250Hz) on the bridged channels so the sub only plays bass.

Yes. The circuit board is conformal coated against moisture, salt air, and humidity, and all the hardware is stainless steel. The included white silicone terminal covers seal the power, ground, remote, and RCA connections against spray and salt corrosion. The chassis is UV and salt resistant.

At 8.86" x 4.92" x 1.81", it's small enough to fit under a console, behind a side panel, or beneath a seat where a full-size amp won't go. Mounting hardware is included.

It's built to be easy on the battery. The Class D design runs at 80% efficiency at 4 ohms and draws only 1 amp at idle, so more of the battery's power goes to the music instead of heat. It runs on anywhere from 9 to 16.1 volts.

The MRDF-3 has 4 AWG power and ground terminals and 10 AWG speaker terminals, with two 20A internal fuses (40A total). A wiring kit isn't included, so plan on a 4 AWG marine amp kit for the install.

The input sensitivity adjusts from 0.2V to 6.05V, so it matches both low-output and high-output head units through the RCA inputs. Tiffany-style RCA jacks keep the connections tight on rough water and help prevent corrosion.

Pick Full Range, Low Pass, or High Pass for each pair of channels, then set the filter anywhere from 50Hz to 250Hz. High pass keeps deep bass away from small marine speakers so they can play louder and cleaner. The clip LED lights up when you push into distortion, and built-in thermal, short-circuit, and over-voltage protection keep the amp safe.