Rockford Fosgate
400W RMS 4-Channel Marine Amplifier

Rockford Fosgate PM400X4
Rockford Fosgate PM400X4 Rockford Fosgate PM400X4 Rockford Fosgate PM400X4 Rockford Fosgate PM400X4 Rockford Fosgate PM400X4 Rockford Fosgate PM400X4 Rockford Fosgate PM400X4 Rockford Fosgate PM400X4


The PM400X4 is a 400 Watt 4-channel amplifier with high dynamic power using Class-A/B technology and a conformal coated pc board designed for motorsport and marine applications.

The PM400X4 is perfect for 4-way front-stage/rear-fill or 3-way front-stage/subwoofer systems. Simply drop a pair of component speakers on the front channels and subs on the rear and BOOM - you got "The PUNCH." With its flexible design, the PM400X4 is an excellent amplifier choice for virtually any vehicle.

  • Features C.L.E.A.N. Set-up
  • High Level Input Capable with Auto Turn-On Circuit
  • On-board Punch EQ with +18dB boost @ 45Hz
  • 12dB/octave Butterworth Crossover
  • Cast Aluminum Heatsink
  • Muted Turn On
  • Short Circuit Protection
  • Stealth Top Mounted Control Panel
  • Over Current Protection
  • Marine Grade Stainless Steel Hardware
  • Marine Grade Two Part Epoxy Coating on Circuit Boards
  • 2-Year Warranty

CTA-2006 Compliant

Power ratings on Rockford Fosgate amplifiers conform to CTA-2006 industry standards. These guidelines mean your amplifier's output power ratings are REAL POWER numbers, not inflated marketing ratings.

CE Compliant

This product fulfills all essential safety and environmental requirements as defined in the European Directives (768/2008 EC).


TRANS•ana is a Class A/B topology that simplifies the signal path of the amplifier allowing the signal to travel through the amplifier at a lower voltage. The result is greater reliability and exceptional sound quality.

Balanced Differential Inputs

Differential inputs eliminate noise picked up by signal cables.


Dynamic Thermal Management evenly distributes excess heat across entire amplifier heatsink.

Element Ready™

All components are protected against harsh outdoor elements like Dust, UV, Temperature, Water, Corrosion and Vibration.


DSM utilize 1% tight-tolerances improving efficiency of the circuit, decreases cross-talk from other discrete components and lowers operating temperature.


NOMAD is a "real time" analog computer that protects your amplifier from shorting speaker wires and dangerously low speaker impedances.


MEHSA³ reduces MOSFET temperatures, lowers distortion, increases durability and prolongs the output device life span.

C.L.E.A.N. Set-Up

C.L.E.A.N. (Calibrated Level Eliminates Audible Noise) is a patented circuit with in/out clip LEDs to help match a source to amp and optimize output.

Engineered in the USA

These Avatars are a personal signature from the Rockford Fosgate team member(s) who designed and engineered this fanatic product. This statement illustrates our commitment to being Designed and Engineered in the U.S.A.


400W RMS
50W RMS x 4 @ 4Ω
100W RMS x 4 @ 2Ω
200W RMS x 2 @ 4Ω Bridged
Dynamic Power
82W RMS x 4 @ 4Ω
137W RMS x 4 @ 2Ω
266W RMS x 2 @ 4Ω Bridged
Frequency Response
20Hz - 20kHz
Input Sensitivity
150 mV - 12 V
67% @ 4Ω
Total Harmonic Distortion
4Ω: <1.0%
2Ω: <1.0%
Signal Input
Hi/Low Level: 2 RCA Pair
Signal Output
Tone Controls
Front Punch EQ2 Bass: 0dB to +18dB @ 45Hz
Front Punch EQ2 Treble: 0dB to +12dB @ 12.5kHz
Rear Punch EQ2 Bass: 0dB to +18dB @ 45Hz
Rear Punch EQ2 Treble: 0dB to +12dB @ 12.5kHz
Function Depends upon LP/AP/HP Switch Position
Crossover Controls
Front High-Pass/Low-Pass (HP/LP): 50Hz-250Hz @ 12dB/octave Butterworth
Rear High-Pass/Low-Pass (HP/LP): 50Hz-250Hz @ 12dB/octave Butterworth
All-Pass: Yes
Remote Control
Power Wire Gauge
8 AWG to 4 AWG
Power Input Connector
Captive C-Clamp
Speaker Wire Gauge
8 AWG to 18 AWG
Speaker Output Connector
Captive C-Clamp
Operating Voltage
9 - 16 VDC
Recommended Fuse
60 A
Average Current Draw
30 A
Max. Current Draw
60 A
Suggested Alternator
75 A
2.38" x 7.76" x 11.03"
6.05 x 19.71 x 28.02 cm
10.8 lbs (4.89 kg)
More Information
Brand Rockford Fosgate
Amplifier Class Class AB
RMS Power 400W RMS