Marine amplifier MHD750/1

The JL Audio MHD750/1 amplifier is a single-channel Class D model designed for marine audio systems. It delivers 750 watts RMS.

This wideband amplifier is designed to cover an extended frequency response, ranging from 6 Hz (very deep bass) to 8 kHz (lower treble range).

Although specifically designed for marine applications, the MHD750/1 amplifier is not waterproof. It must not be installed in a location where it could get wet and must be mounted in a dry, well-ventilated environment.

The MHD750/1 amplifier uses JL Audio’s exclusive R.I.P.S. (Regulated Intelligent Power Supply) power supply technology. This design optimizes amplifier output across any impedance between 1.5 and 4 ohms, ensuring optimal performance with a wide range of speaker systems.

Yes, thanks to its wideband design, the MHD750/1 can be used as a subwoofer amplifier, but also as a very powerful amplifier for mid-bass or midrange drivers. It is even possible to use a second HD750/1 to form a stereo pair.

Yes, the preamplifier section of the MHD750/1 amplifier is equipped with outputs that can send pass-through signals from the inputs to power additional amplifiers in your marine audio system.

This amplifier is designed to operate in vessels with 12-volt negative-ground electrical systems. Using the product in positive-ground vessels and/or with voltages other than 12V may damage the unit.

For optimal cooling performance, the amplifier’s outer casing must be exposed to as large a volume of air as possible. If the amplifier is mounted under a seat, ensure there is at least 2.5 cm (1 inch) of clearance above its outer casing to allow adequate cooling. Mounting it upside down is strongly discouraged.

Use a 4 AWG power cable for lengths over 180 cm (72 inches). An 8 AWG cable is acceptable for shorter lengths. If multiple amplifiers are installed and powered by the same main cable, use a main cable of 2 AWG or 1/0 AWG with a power distribution block. Use only pure copper wire, not CCA (Copper-Clad Aluminum) wire.

The positive power cable must be protected by an appropriate fuse (60A for a single MHD750/1) and a fuse block, installed within 45 cm (18 inches) of the battery’s positive terminal. This fuse is essential to protect the vessel.

The amplifier must be installed in a dry and well-ventilated environment. It must be securely mounted to prevent detachment. Avoid mounting it in the engine compartment or any other area that would expose the amplifier's circuits to the elements. Do not drill through the hull, fuel tank, fuel lines, or wiring harness.

It is strongly advised against mounting the amplifier upside down, as this can impair its cooling efficiency and performance.

All system cables must be protected from sharp edges (metal, fiberglass, etc.) by routing them carefully, securing them, and using grommets and sleeves where necessary. Never route system wiring externally or beneath the vessel, as this is a hazardous practice.

Yes, before installing the amplifier, it is essential to disconnect the negative wire (ground) from the ship’s battery. This prevents accidental damage to the system, the vessel, and the person during installation.

No, this amplifier is specifically designed to operate with 12-volt negative-ground electrical systems. Using it with different voltages or positive-ground systems will void the warranty and may damage the product.

It is possible to use a second HD750/1 to form a stereo pair. However, you must not attempt to "bridge" the outputs of this amplifier with the outputs of a second amplifier, even if identical, to increase power on a single channel.

Yes, JL Audio's R.I.P.S. power supply design optimizes amplifier output for any speaker impedance between 1.5 and 4 ohms, ensuring compatibility with a wide range of speaker systems.

No, this product is neither certified nor approved for use in aircraft.

Yes, using this amplifier on vessels with a positive ground and/or voltages other than 12V may damage the product and will void the warranty.

If your amplifier requires servicing, contact your authorized JL Audio dealer for assistance. Keep the product serial number handy; it is located on the bottom panel of the amplifier and on its packaging.