







"Fit perfectly and worked exactly as expected — support was excellent."
Rockford Fosgate TM400X4AD
Upgrade Your Vehicle With Confidence. This Is Built to Fit, Perform, and Last
Rockford Fosgate TM400X4AD: 4-Channel Marine Amplifier for Powerful, Reliable Sound
The Rockford Fosgate TM400X4AD is a high-performance 400-watt 4-channel marine amplifier engineered to deliver powerful, reliable sound on the water. As part of Rockford Fosgate’s advanced Power Marine Series, this amplifier merges innovative technology with a rugged, marine-ready design—ideal for demanding marine audio environments.
Powerful, Dynamic Sound with Marine-Ready Durability
The TM400X4AD delivers 400 watts of RMS power to ensure bold, crystal-clear audio in open water conditions. Featuring Rockford Fosgate’s proprietary Class AD technology, it offers the efficiency of Class D with the sound quality of Class AB—minimizing distortion and heat. Built with a corrosion-resistant, marine-grade aluminum chassis, this amplifier is perfectly suited for boats and other marine vessels.
Compact and Versatile Design
With its compact footprint, the TM400X4AD fits easily into tight installation spaces, making it ideal for vessels where space is at a premium. Despite its small size, its rugged build quality ensures long-term durability and consistent performance under extreme marine conditions.
Precision Controls for Customized Sound
The amplifier features fully adjustable high-pass and low-pass crossovers, a Punch EQ boost, and Rockford’s C.L.E.A.N. (Calibrated Level Eliminates Audible Noise) setup system. These tools give you the ability to fine-tune your system for optimal audio performance and minimize distortion, tailored to your exact environment and preferences.
Key Features
- 400 Watts RMS Output: Provides rich, dynamic sound across four channels.
- Class AD Efficiency: Blends Class D efficiency with Class AB sound fidelity.
- Marine-Grade Construction: Corrosion-resistant aluminum chassis built for marine environments.
- Compact Design: Slim footprint for easy installation in boats and tight compartments.
- Advanced Tuning Options: High-pass/low-pass crossovers, Punch EQ, and C.L.E.A.N. system for precise control.
Why Choose the Rockford Fosgate TM400X4AD?
Ideal for marine audio enthusiasts, the TM400X4AD offers a rare mix of power, compact size, and rugged marine durability. Its cutting-edge design makes it perfect for building or upgrading an audio system on any watercraft, delivering full-range sound performance that cuts through the waves and wind.
Upgrade Your Marine Audio with the Rockford Fosgate TM400X4AD
Ready to experience crystal-clear, powerful sound on the water? Order the Rockford Fosgate TM400X4AD today and enhance every voyage with high-performance audio built to endure the marine environment.
Specifications
- Power Output: 100W RMS x 4 @ 4 Ohms, 100W RMS x 4 @ 2 Ohms, 200W RMS x 2 @ 4 Ohms Bridged
- Frequency Response: 20 Hz – 20 kHz
- Signal-to-Noise Ratio: >80 dB
- Crossover: Variable High-Pass and Low-Pass (50 Hz – 500 Hz @ 12 dB/octave)
- Punch EQ: +0–18 dB Boost @ 45 Hz
- Dimensions: 1.6" x 4.3" x 8.3" (4.06 cm x 10.92 cm x 21.08 cm)
- Input Sensitivity: High-Level: 150 mV – 4V, Low-Level: 150 mV – 4V
- Amplifier Class: AD
- Marine Protection: Corrosion-resistant aluminum chassis
Frequently Asked Questions
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What is the Rockford Fosgate TM400X4AD?
A compact, marine-ready 4-channel amplifier that delivers 400 watts of powerful, clean audio with advanced efficiency and durability. -
Can the TM400X4AD drive multiple speakers?
Yes. It can power up to four speakers individually or be bridged to power two high-powered subwoofers, offering system flexibility. -
What makes the TM400X4AD unique?
The use of Class AD technology, combined with its compact marine-grade construction, gives it high efficiency, low heat output, and robust performance in marine settings. -
Is it easy to install?
Absolutely. Its compact form and versatile mounting options make installation simple, especially in space-restricted boat compartments. -
Why choose this amp for marine audio?
For marine-grade power and clarity with efficient operation, the TM400X4AD is an ideal upgrade for audio systems exposed to moisture, salt, and vibration.
Experience Powerful, Reliable Sound on the Water with the Rockford Fosgate TM400X4AD
Order now and transform your marine audio setup with this high-performance, rugged amplifier built to deliver exceptional sound on every open-water adventure.
- Ships within 1–3 business days from our warehouse
- Tracking included with every order
- Free 30-day returns if it doesn’t work for your setup
- 2-year manufacturer warranty
- Authorized dealer guarantee
- Real installer-backed support before and after purchase

Why This Upgrade Makes Daily Driving Better
Ease of Use & Safety
Expandable by Design
FITMENT & INSTALLATION MADE SIMPLE
WHAT VEHICLES IT WORKS WITH
We verify compatibility before you buy, no guesswork.
DIY FRIENDLY IF:
- You're comfortable with basic tools
- You follow provided instructions
PROFESSIONAL INSTALL RECOMMENDED IF:
- Your vehicle requires dash kits or wiring adapters
- You want a turnkey experience
INSTALLATION CREDIT & SUPPORT:
- $75 Installation Credit when purchased online
- Speak to real installers before you buy
- Bring it into one of our locations for install
Why Buying This Here Is Safer Than Anywhere Else
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Physical stores & real installers
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FREQUENTLY ASKED QUESTIONS
FREQUENTLY ASKED QUESTIONS
How do I know this stereo or speaker will fit my car?
Select your year, make, and model using the Vehicle Fit Guide at the top of the page. You’ll only see products that are compatible with your exact vehicle setup.
What happens if I order something that doesn’t fit?
You can return or exchange it within 30 days. We’ll help you identify the correct part for your vehicle so you don’t have to guess again.
Are these products brand new and covered by warranty?
Yes — all products are brand new, authentic, and sold as an authorized dealer, which means they include a full manufacturer warranty.
Can you install this for me, or do I need to do it myself?
You can do either. Install it yourself, or use your $75 installation credit at our shop and have it professionally installed by our team.
What if I don’t know what to choose for my car?
Tell us your vehicle and what you want to improve (sound, bass, CarPlay, etc.). We’ll recommend the exact products that fit your car and your budget.
