Rockford Fosgate M2-300X4 M2 Series 300 Watt 4-Channel Full-Range Class-D Element Ready Marine Amplifier

A marine grade 300W 4-channel Full-Range Class-D amplifier delivering 75W x 4 at 2-ohm or 150W x 2 at 4-ohm bridged (CTA-2006 rated). Features independent front and rear channel crossover control with all-pass mode, 2/4 channel input selection switch, RCA pass-thru outputs, C.L.E.A.N. gain calibration, NOMAD speaker protection, MEHSA4 heat management, and conformal coated circuit board. Backed by a 2 year warranty.

Product Overview

The Rockford Fosgate M2-300X4 is a 300W 4-channel Full-Range Class-D marine amplifier from the M2 Element Ready series, purpose-built for powering marine speaker pairs across the full audio spectrum. Full-Range Class-D topology delivers efficient power delivery across a 20Hz-20kHz frequency response while reducing current demand on the vessel's electrical system. Rated continuous power is 50W x 4 at 4-ohm, 75W x 4 at 2-ohm, or 150W x 2 at 4-ohm bridged (CTA-2006, less than 1.0% THD+N). Dynamic power via PowerCube reaches 70W x 4 at 4-ohm, 115W x 4 at 2-ohm, and 230W x 2 at 4-ohm bridged.

The M2-300X4 provides independent front and rear channel crossover control, each with fully adjustable high-pass and low-pass filters at 12dB/octave Butterworth (50Hz-250Hz) and an all-pass mode. A 2/4 channel input selection switch configures the amplifier for source units with either 2 or 4 RCA outputs, working for both RCA and high-level inputs. RCA pass-thru outputs allow downstream amplifier chaining - the M2-500X1 subwoofer amplifier is the natural companion for a complete marine speaker and subwoofer system. Auto-Sense turn-on activates the amplifier when a speaker-level signal is detected, with a RAP bypass switch for Retained Accessory Power systems.

The circuit board is conformal coated against dust and water, and the UV stable powder coated cast aluminium heatsink provides environmental protection. Zinc nickel-plated marine grade brass connection terminals resist corrosion. NOMAD speaker protection, MEHSA4 heat management, and per-channel C.L.E.A.N. clip indicators for both front and rear channels are all active throughout. RATS tested and optimised using AudioGraph PowerCube.

Features & Benefits

Full-Range Class-D - Efficient 4-Channel Marine Amplification: Full-Range Class-D topology delivers high-efficiency power across the complete 20Hz-20kHz audio spectrum, reducing current demand on the vessel's electrical system while powering marine speaker pairs with clean, accurate output.

Independent Front and Rear Crossover Control with All-Pass Mode: Front and rear channels each have independent high-pass and low-pass crossover controls at 12dB/octave Butterworth (50Hz-250Hz), plus an all-pass mode for full-bandwidth output. This provides more flexibility than the M2-200X2 which shares a single crossover setting across both channels.

2/4 Channel Input Selection Switch: The input selection switch configures the M2-300X4 to accept either a 2-channel or 4-channel RCA or high-level input, working with source units that have limited RCA output pairs without requiring Y-cables or signal splitting.

RCA Pass-Thru Outputs for Downstream Chaining: RCA pass-thru outputs are active with both RCA and high-level input, allowing the signal to be passed to a downstream subwoofer amplifier such as the M2-500X1 without signal degradation or Y-cable noise.

C.L.E.A.N. Technology - Independent Per-Channel Clip Monitoring: C.L.E.A.N. provides separate input and output clip indicator LEDs for both the front and rear channel groups, enabling accurate independent gain calibration across all four channels.

Bridgeable to 2-Channel - 150W Mono per Pair: The M2-300X4 can be bridged to 2-channel, delivering 150W x 2 at 4-ohm bridged (230W dynamic), suited to driving two higher-power marine speakers or running a compact 2-channel wake tower speaker installation.

Auto-Sense Turn-On with RAP Bypass: Auto-Sense activates the amplifier automatically when a high-level input signal is detected, removing the need for a dedicated remote turn-on wire. A bypass switch is included for vessels with Retained Accessory Power systems.

NOMAD, MEHSA4, and Conformal Coated Circuit Board: NOMAD provides real-time protection against shorted speaker wires and dangerously low impedances. MEHSA4 reduces MOSFET temperatures, lowers distortion, and extends output device life. The conformal coated circuit board protects against dust and water ingress at the PCB level.

Technical Specs

Specification	Detail
SKU	M2-300X4
Number of Channels	4
Total Power	300W
Rated Power - 4-ohm (CTA-2006, less than 1.0% THD+N)	50W x 4
Rated Power - 2-ohm (CTA-2006, less than 1.0% THD+N)	75W x 4
Rated Power - 4-ohm Bridged (CTA-2006)	150W x 2
Dynamic Power - 4-ohm (PowerCube)	70W x 4
Dynamic Power - 2-ohm (PowerCube)	115W x 4
Dynamic Power - 4-ohm Bridged (PowerCube)	230W x 2
Circuit Topology	Full-Range Class-D
Bridgeable	Yes
Frequency Response	20 Hz - 20 kHz
THD + Noise	Less than 1.0% at 4-ohm and 2-ohm
Input Sensitivity	Low-Level: 150mV - 4V / High-Level: 450mV - 12V
Signal Input	Front: 2 x RCA + 4-Pin Molex / Rear: 2 x RCA + 4-Pin Molex
Input Selection	2/4 Channel Switch (RCA and High-Level)
Signal Output	2 x RCA Pass-Thru (active with RCA or High-Level input)
Tone Controls	None
Front High-Pass Crossover	50 Hz - 250 Hz at 12dB/Octave Butterworth
Front Low-Pass Crossover	50 Hz - 250 Hz at 12dB/Octave Butterworth
Rear High-Pass Crossover	50 Hz - 250 Hz at 12dB/Octave Butterworth
Rear Low-Pass Crossover	50 Hz - 250 Hz at 12dB/Octave Butterworth
All-Pass	Yes
Remote Controls	None
Auto-Sense Turn-On	Yes (with RAP bypass switch)
Power Wire Gauge	4 AWG
Power Input Connector	Compression Terminal Block
Speaker Wire Gauge	8 AWG
Speaker Output Connector	Compression Terminal Block
Terminals	Zinc Nickel-Plated Marine Grade Brass
Cooling	Convection
Heatsink	UV Stable Powder Coated Cast Aluminium (Focused Mass)
Circuit Board Protection	Conformal Coated
Operating Voltage	9 - 16 VDC
Recommended Fuse (not included)	60A
Max Current Draw at 13.8V Sinewave	39A
Visual Indicators	Power/Protect / C.L.E.A.N. In / C.L.E.A.N. Out (Front and Rear)
Dimensions (H x W x D)	49 x 173 x 255mm (1.9 x 6.8 x 10.1 inch)
Shipping Weight	2.15kg
CTA-2006 Compliant	Yes
Quality Testing	RATS (Rockford Automated Testing System)
Warranty	2 Years

Compatible With / Goes Well With

The M2-300X4 suits marine watercraft and powersports applications requiring an efficient 4-channel full-range marine amplifier for speaker pairs. At 39A maximum current draw and a 60A fuse requirement, it places moderate demand on the vessel's electrical system. The RCA pass-thru output pairs naturally with the M2-500X1 mono subwoofer amplifier for a complete M2 series speaker and subwoofer system.

Goes Well With:

M2-500X1 - Companion M2 series 500W mono subwoofer amplifier, chainable via the M2-300X4's RCA pass-thru outputs for a complete M2 series marine system
PMX-1 - Rockford Fosgate Punch marine media receiver, a clean source unit pairing with the M2-300X4 via 2-channel RCA using the 2/4 input switch
M2-8H - M2 series 8 inch Color Optix marine horn speakers, powered by the M2-300X4's four channels
M2WL-8 / M2WL-8B - M2 series wake tower speakers for powering via the full-range channels of the M2-300X4
M2-750X5 - Alternative single-unit M2 series 5-channel amplifier for builds requiring an integrated subwoofer channel alongside speaker amplification
RFW4R / RFW4B - Rockford Fosgate 4 AWG marine amplifier wiring kits (red or black) matched to the M2-300X4's 4 AWG power wire requirement

Frequently Asked Questions

What is the difference between the M2-300X4 and the M2-200X2?

Both are M2 Element Ready Full-Range Class-D marine amplifiers, but the M2-300X4 adds two additional channels, independent front and rear crossover control, a 2/4 channel input selection switch, and per-channel C.L.E.A.N. output indicators for both front and rear. The M2-200X2 delivers 100W x 2 at 2-ohm across its two channels, while the M2-300X4 delivers 75W x 4 at 2-ohm across four channels. Choose the M2-300X4 for installations requiring four independently controlled speaker channels; choose the M2-200X2 for simpler 2-channel builds or where two bridged channels are sufficient.

What does the 2/4 channel input selection switch do?

The input selection switch configures the M2-300X4 to accept either a 2-channel or 4-channel input from the source unit, working for both RCA and high-level connections. In 2-channel mode, the single front RCA pair feeds all four channels internally. In 4-channel mode, separate front and rear RCA pairs are used for independent left/right front and rear channel control. This removes the need for Y-cables when the source unit has only a single stereo RCA output.

Can I add a subwoofer amplifier to a system using the M2-300X4?

Yes. The M2-300X4 includes RCA pass-thru outputs that are active with both RCA and high-level input, allowing a distortion-free signal to be passed to a downstream subwoofer amplifier such as the M2-500X1. The two amplifiers chain together cleanly for a complete 4-channel speaker plus mono subwoofer marine audio system.

What fuse does the M2-300X4 require and is it included?

The M2-300X4 requires a 60A fuse, which is not included in the box and must be sourced separately. This is larger than the 30A fuse on the M2-200X2 but smaller than the 80A on the M2-500X1, reflecting the M2-300X4's 39A maximum current draw. Install the fuse as close to the battery as possible in the 4 AWG power supply line.

Does the M2-300X4 require a dedicated remote turn-on wire?

Not necessarily. Auto-Sense activates the amplifier automatically when a high-level speaker signal is detected at the input, removing the need for a separate remote wire in OEM integration scenarios. A RAP bypass switch is included for vessels where the source unit continues to output a signal after the ignition is switched off, preventing the amplifier from remaining on unintentionally.

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