Rockford Fosgate M5-800X4 4-Channel Marine Amplifier

The Rockford Fosgate M5-800X4 is a compact four-channel amplifier designed for marine, motorcycle, and powersports audio systems. It provides dedicated amplification for up to four full-range speakers while using an Element Ready design suited to exposed installations. Its compact chassis helps solve mounting challenges where space is limited.

This amplifier is intended for riders, boaters, and off-road enthusiasts building a powered speaker system that needs to operate in demanding outdoor conditions. It delivers 100 watts RMS per channel at either 2 or 4 ohms, with bridge capability for compatible 4-ohm speaker loads. Dynamic Power ratings provide additional output measurement under the CTA-2006 standard.

The M5-800X4 uses Class-AD amplification and Rockford Fosgate Constant Power technology for stable output across supported speaker impedances. Its frequency response spans 10 Hz to 50 kHz, allowing it to support full-range speaker applications. Adjustable high-pass and low-pass crossovers help match the amplifier to the speakers and role it serves in the system.

Element Ready construction includes IPX6 water-spray protection, sealed harness connections, and a protected top-mounted control panel. The C.L.E.A.N. setup system uses input and output clip indicators to assist with level matching. Balanced differential inputs and signal-sense/DC-offset turn-on support integration with OEM and aftermarket source units.

Use the M5-800X4 to power front and rear speakers, a four-speaker marine zone, or two bridged speaker channels where system design permits. A PRESET switch supports select Rockford Fosgate UTV audio-kit applications, while manual controls remain available when the preset is off. Its compact size and integrated harness arrangement make it suitable for installations where conventional amplifier terminals are difficult to access.

Key Features

• Four-Channel Output: Powers four speakers or supports two bridged channels.
• Element Ready Design: IPX6 water-spray protection supports outdoor audio installations.
• Class-AD Topology: Delivers efficient full-range amplification in a compact chassis.
• Constant Power: Maintains output across supported 2- and 4-ohm loads.
• C.L.E.A.N. Indicators: Input and output clip LEDs assist level setup.
• Adjustable Crossovers: High-pass and low-pass filters help tailor speaker operation.

Design & Installation

The M5-800X4 has a 1.7-inch-high chassis with IPX6 water-spray protection, integrated sealed harnesses, and a smoked control-panel cover. Its focused-mass heat sink concentrates aluminum around critical internal components. The top-mounted controls are protected while remaining accessible for setup.

Plan for an external power and ground connection using 8 AWG cable, plus individually fused amplifier power wiring. The amplifier accepts RCA low-level or high-level input through its harness system and includes adapters for installation. For full-range speakers, set the crossover to high-pass as appropriate; use bridged channels only with compatible 4-ohm loads and follow the manufacturer wiring guidance.