Rockford Fosgate TM400X4ad Power Marine 400 Watt Class-ad 4-Channel Amplifier

Rockford Fosgate TM400X4ad Power Marine 400W Class-AD 4-Channel Amplifier Constant Power, Four Channels, Ultra-Compact

Product Overview

The Rockford Fosgate TM400X4ad is a 400 Watt 4-channel amplifier from the Power Marine series, built on Rockford Fosgate's proprietary Class-AD technology with Constant Power output at both 4-ohm and 2-ohm impedance loads. The 4-channel counterpart to the TM400X2ad, it extends the Constant Power advantage of Class-AD across four output channels powering a complete four-speaker marine or powersport system with consistent, predictable output regardless of whether 4-ohm or 2-ohm speakers are connected.

Housed in the same ultra-compact chassis format as the rest of the Power Marine TM-series range, the TM400X4ad features dual fan forced induction cooling and a three-stage thermal lock extrusion heatsink managing the thermal demands of four Class-AD channels in the enclosed, high-temperature installation environments of marine vessels and powersport vehicles. A 2/4 channel input switch, 4-ohm bridged capability, differential high-level inputs with Auto Turn-On, Remote-Out, upgraded RCA connectors, C.L.E.A.N. input/output clip detection, real-time thermal sensing, and marine-grade two-part epoxy conformal PCB coating complete a 4-channel Power Marine amplifier built to power a full system in a single compact unit.

Key Specifications

• Channels: 4
• Total power: 400W
• Circuit topology: Class-AD (Rockford Fosgate proprietary)
• Constant Power: Yes same output at 4-ohm and 2-ohm
• Bridgeable: Yes 4-ohm bridged
• Input switch: 2/4 channel
• Cooling: Dual fan forced induction + dual extruded heatsinks + 3-stage thermal lock extrusion
• Inputs: Low-level RCA + high-level differential (with auto turn-on)
• Remote-Out: Yes (when using high-level inputs)
• Power/Ground connector: 8 AWG
• RCA connectors: Upgraded
• C.L.E.A.N.: Input + output clip detection with LED indicators
• Thermal protection: Real-time thermal sensing
• Control panel: Top-mounted
• Circuit board protection: Marine-grade two-part epoxy conformal coating
• Construction: Discrete surface mount technology
• Rated power: Confirm with supplier
• CEA-2006 compliant: Confirm with supplier
• Dimensions: Confirm with supplier
• Shipping weight: Confirm with supplier

Features & Benefits

• Rockford Fosgate proprietary Class-AD technology with Constant Power across four channels: Class-AD delivers the same output power at both 4-ohm and 2-ohm speaker impedances across all four channels simultaneously. For marine builds running 4-ohm or 2-ohm speakers in any combination across four positions, Constant Power ensures consistent, predictable output without impedance recalculation a practical advantage when mixing speaker brands or impedances in a multi-zone marine system.
• 4-channel full-range coverage for complete marine system builds: Four output channels power a complete four-speaker marine installation dash speakers, cockpit speakers, transom-mount speakers, or wakeboard tower speakers from a single compact amplifier without the complexity of multiple separate units.
• 2/4 channel input switch: Drive all four output channels from just two RCA inputs when the source unit has limited preamp outputs. Eliminates the need for Y-adapters in marine and powersport installs where head unit RCA outputs are often restricted consistent with the feature set of the PM600X4 and PM1000X5 in this catalogue.
• 4-ohm bridged capability: Bridge channel pairs to mono for high-power 2-channel or dedicated subwoofer driving, extending the TM400X4ad's system configuration flexibility beyond standard 4-channel stereo operation.
• Ultra-compact chassis: The same space-efficient compact format as the TM400X2ad and TM500X1br Power Marine amplifiers purpose-designed for the restricted mounting locations of marine vessels, UTVs, and powersport vehicles where conventional 4-channel amplifier footprints create fitment challenges.
• Dual fan forced induction cooling: Active forced air cooling via dual fans manages the thermal output of four Class-AD channels in enclosed, low-airflow marine and motorsport installation environments where passive convection cooling alone would be insufficient.
• Three-stage thermal lock extrusion with dual extruded heatsinks: Multi-stage passive heatsink design working in combination with the dual fans for comprehensive thermal management across four channels within the compact chassis.
• Real-time thermal sensing: Continuous temperature monitoring with real-time protection response, safeguarding all four channels during sustained high-output operation in elevated ambient temperatures.
• C.L.E.A.N. input and output clip detection with LED indicators: Simultaneous input and output THD monitoring across the amplifier for accurate gain structure setup and ongoing clip detection during use consistent with the TM-series standard and a step above the Punch Marine range.
• Differential high-level inputs with Auto Turn-On: Differential design rejects common-mode noise and ground loop interference common in marine electrical systems. Auto Turn-On eliminates the need for a dedicated remote wire ideal for OEM integration across the full range of Australian marine vessel and powersport vehicle head unit configurations.
• Remote-Out feature: Outputs a remote turn-on signal to downstream amplifiers or accessories when using high-level inputs useful for multi-amplifier marine system builds where a subwoofer amplifier needs to be triggered without a dedicated head unit remote output.
• Upgraded RCA connectors: Higher-quality connectors reducing signal degradation and improving long-term reliability in the vibration and moisture conditions of marine installations.
• Marine-grade two-part epoxy conformal PCB coating: Circuit boards sealed against moisture, salt spray, and humidity consistent with the conformal coating standard across the Rockford Fosgate Power Marine and Punch Marine amplifier ranges.
• Discrete surface mount technology construction: Compact, vibration-resistant circuit board assembly contributing to both the ultra-compact chassis dimensions and long-term reliability in high-vibration marine and motorsport environments.
• 8 AWG power/ground connectors: Appropriate wiring gauge for the current demands of a 400W 4-channel amplifier.

Technical Specs

Compatible With

• Marine vessels: bow riders, pontoons, ski boats, fishing boats, tinnies, and jet skis with four-speaker systems
• Powersport applications: UTVs, side-by-sides, dune buggies, and off-road 4WDs with full four-speaker builds
• Factory and aftermarket marine head units with RCA or high-level outputs
• Rockford Fosgate Punch and Prime marine speakers 4-ohm or 2-ohm (all four channels)
• Rockford Fosgate TM500X1br Power Marine mono amplifier (for combined 4-channel full-range + mono subwoofer system builds)
• Downstream amplifiers triggered via Remote-Out in multi-amplifier marine system configurations
• Vessels and vehicles where a compact 4-channel amplifier with OEM integration capability is required

Frequently Asked Questions

What is the difference between the TM400X4ad and TM400X2ad? Both are Power Marine Class-AD amplifiers with Constant Power output at 4 and 2 ohms, identical chassis, dual fan cooling, and the same feature set. The TM400X4ad has four output channels for powering a complete four-speaker system, while the TM400X2ad has two output channels. The TM400X4ad also adds a 2/4 channel input switch not present on the TM400X2ad. Choose the TM400X4ad for four-speaker coverage; choose the TM400X2ad for a two-speaker or dedicated bridged mono application.

What does Constant Power mean for speaker pairing in a marine build? Constant Power means the TM400X4ad delivers the same output across all four channels regardless of whether 4-ohm or 2-ohm speakers are connected. This removes the need to recalculate expected power output when mixing speaker impedances across different positions on the vessel simplifying system design and ensuring consistent volume levels across all four channels.

Can the TM400X4ad be bridged to drive a subwoofer? Yes. The TM400X4ad is bridgeable to 2-channel mono into 4-ohm loads, allowing a channel pair to drive a subwoofer while the remaining two channels continue to power full-range speakers enabling a 3-channel system configuration from a single 4-channel amplifier. Confirm the minimum bridged impedance with your supplier before connecting.

What does the 2/4 channel input switch do? It allows two RCA inputs to feed all four output channels simultaneously. When a marine head unit has only one stereo RCA preamp output, the 2/4 channel input switch eliminates the need for Y-adapters simplifying wiring and reducing signal path components in the installation.

Is the TM400X4ad suitable for saltwater marine environments? Yes. Marine-grade two-part epoxy conformal-coated circuit boards and the active dual fan cooling system make the TM400X4ad suitable for open saltwater and estuarine environments. The conformal coating resists moisture, salt spray, and humidity, while the active cooling manages heat in enclosed installation spaces where passive cooling would be insufficient.