Marine amplifier MV400/4i

The JL Audio MV400/4i amplifier is a marine-grade Class D 4-channel model designed for demanding environments. It features second-generation NexD2™ technology and a digital signal processor (DSP) for high-quality audio amplification and high efficiency.

The MV400/4i amplifier is a 400-watt model, offering amplification across 4 channels. It is designed to deliver significant power for your marine audio system.

This amplifier uses NexD2™ technology, the second generation of JL Audio’s high-speed switching technology. It also integrates a digital signal processor (DSP) for advanced sound management.

The amplifier and its integrated DSP settings are configured using an external device (PC, tablet, or phone) with the appropriate JL Audio TüN™ application installed. Connection is made via the amplifier's USB A/B port.

NexD2™ technology delivers reference-class audio amplification with exceptional efficiency. It enhances sound quality and optimized performance of the amplifier in a compact form factor.

Yes, when mounted vertically with all connections pointing downward, the MV400/4i amplifier achieves an IPX2 water resistance rating. This means it is protected against vertically falling water droplets.

The amplifier’s outer casing is designed to dissipate heat from the circuits. For optimal cooling performance, it must be exposed to as large a volume of air as possible. If the amplifier is installed in an enclosed compartment, it is recommended to leave at least 2.5 cm (1 inch) of clearance above the outer casing to ensure adequate cooling.

The MV400/4i amplifier housing contains the following items:

An amplifierA power input connectorTwo high-level speaker output harnessesA USB A/B cable (1.8 m / 6 ft)A connection guideFour mounting screwsA 2.5 mm hex keyA 3 mm hex key

Yes, the amplifier has reset buttons. You can perform a factory reset by holding the button down for 7 seconds (this will erase all user settings), or simply restart the amplifier by pressing and releasing the button (previous settings will be retained).

The amplifier should be installed in a dry, well-ventilated location that does not interfere with factory-installed systems. Avoid areas directly exposed to the elements, the engine compartment, extreme heat zones, or near a heater/hot air source. The amplifier must never be submerged or exposed to high-pressure water jets.

MV amplifiers are equipped with keyhole-type mounting holes to simplify installation. It is recommended to position the amplifier vertically, with all connections pointing downward. Wiring should be routed to direct potential condensation and moisture away from the amplifier. Ensure there is also at least 2.5 cm (1 inch) of clearance above the housing if the amp is in an enclosed compartment.

The power connections (+12 VDC and ground) of the MV400/4i amplifier are designed to accept copper wire up to 4 AWG. Tinned copper wire is the best choice for marine installations. The minimum wire gauge for this amplifier is 4 AWG.

An appropriate fuse or an ignition-protected circuit breaker (sold separately) is essential for the boat's safety. If the MV400/4i amplifier is the only device connected to the main power wire, use a 40 A fuse. It must be installed within 18 cm (7 inches) of the battery terminal connection or in accordance with marine industry standards.

To connect the power, ground, and remote start wires to the amplifier, unscrew the adjustment screws on the connector using the supplied hex keys. Strip approximately 10 mm (3/8 inch) of insulation from the end of each wire and insert the stripped wire into the receptacle, securing it firmly. Then tighten each adjustment screw. Finally, plug the power connector into the amplifier's receptacle.

Yes, JL Audio strongly recommends having your amplifier installed by a JL Audio authorized dealer. These professionals have the training, expertise, and equipment required to ensure optimal product performance and a safe installation.

Protect all wires in the system from sharp edges by routing them carefully, securing them, and using grommets and sleeves if necessary. Secure all wiring with cable ties or wire clamps to protect it from moving parts and sharp edges.

This amplifier is designed to operate with 12-volt DC negative-ground electrical systems. Using this product on boats with positive ground or voltages other than 12V DC may damage the unit.

The JLid-COMM port allows connection of optional accessories such as the MVi-HUB, the M-DRC-50, the VXi-BTC, the MVi-DRCADAPT, and other compatible devices.

No, the MV400/4i amplifier is not certified or approved for use with voltages other than 12V DC. Using this product with different voltages may damage the product and will void the warranty.

The amplifier warranty may be void if the product is used on boats with a positive ground, with voltages other than 12V DC, or if used in aircraft. Any damage resulting from incorrect installation or use not compliant with specifications may also void the warranty.