MB Quart Nautic/Offroad 400-Watt Waterproof Monoblock Amplifier
The MB Quart NA4-400.1 Nautic/Offroad 400-Watt Waterproof Monoblock Amplifier is a high-performance mono subwoofer amplifier designed for marine, off-road, and powersports applications. Delivering 400 watts of full-range Class D power, this compact amplifier features waterproof potted internals and IP67-rated protection, ensuring reliable operation even in harsh, moisture-prone environments. The Q-Stasis low-noise preamplifier dramatically reduces incoming signal noise for clean, distortion-free audio, making it ideal for driving subwoofers with precision and clarity.
Engineered for durability and convenience, the NA4-400.1 includes high-temperature, nickel-plated RCA inputs and quick connection power wires for secure, corrosion-resistant installation. Its PWM MOSFET Simpatico Coil power supply delivers stable voltage to Ultra-Fi output devices, while an aluminum heat sink efficiently dissipates heat for extended operation at low impedances. The amplifier features a dial LPF crossover for precise subwoofer signal control, LED protection indicators for thermal, overload, DC, and speaker short faults, and comes with a wired bass remote for easy gain adjustments from any location in the vehicle. This combination of rugged construction, efficient power, and user-friendly controls makes the NA4-400.1 a reliable choice for demanding off-road and marine audio setups.
Features
- Marine Grade Protection / IPX Rating: Meets or exceeds IP67 standards for waterproof and dustproof. Potted Internals: The potting material seals the components, insulating them and ensuring better durability, especially in harsh environments where exposure to moisture or water might otherwise cause short circuits, corrosion, or other performance issues
- Low Noise Preamplifier Circuit: The highly engineered Q-Stasis pre-amplifier stage reduces incoming noise from source units dramatically improving sound quality
- RCA Inputs: 1 pair high temperature impact resistant nickel-plated RCA inputs that allow for secure connections and are corrosion resistant
- Operation Mode: Mono operation
- Crossover Type: Dial LPF: Complete control of amplifier signal, essential when using two or more amplifiers
- Class / Topology: Full Range Class D: Highly efficient circuit topology which helps the amplifier develop a lot of power in a very small heatsink
- Output Device Technology: PWM MOSFET Power Supply: Stable power through the PC board with minimal heat generation
- Heat Sink: Aluminum: Quickly dissipates heat to allow the amplifier to run lower impedance for longer duration
- Power Supply: Simpatico Coil Design: The dual coil Pulse Width Modulated power supply keeps voltage constant through the Ultra-Fi output devices
- Output Connections: Quick Connection Power Wires and RCA Connections
- Connection Type: Nickel-plated connections: Nickel plated corrosion resistant connections
- LED System Protection Circuitry Diagnostics: Protection circuits: Monitor thermal, overload, DC, and speaker short protection with lighted indicators on the amplifier end panel
- Bass Remote Included: Included: Wired Bass Remote allows adjustments to gain level to be made from the control mounted anywhere in the vehicle
Specifications
- Color: Black
- Model Replaced: NA2-400.1
- Warranty: 1 Year
- IPX Rating: IP67
- Compatible Vehicles: Universal
- Amp Class: Full Range Class D
- Amp Total Channels: Mono
- Amp Max Power (watts): 400
- Amp Power @ 2 Ohms (ch x watts): 1 x 400
- Amp Power @ 4 Ohms (ch x watts): 1 x 200
- Amp Crossover: Electronic
- Amp Variable Low Pass Crossover 12dB per Octave: 50Hz-150Hz
- Amp Bass Boost: 0-12dB
- Amp Subsonic Filter: 15Hz-50Hz
- Amp Variable Voltage: 0.2-9V
- Amp Signal to Noise: > 100dB
- Amp Frequency Response: 17Hz-165Hz
- Amp Total Harmonic Distortion (THD): 1.0%
- Amp Speaker Level Audio Inputs: RCA
- Amp Power Terminal 12v/GND: 12 AWG Quick Connector
- Amp Speaker Terminal Wire Gauge: Molex Plug Connector
- Proposition 65 Notice WARNING: This product can expose you to chemicals including LEAD, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
Fitment
- Universal
MB Quart (About)
MB Quart is a leader in premium audio systems for powersports, delivering crystal-clear sound in the most rugged environments. With a focus on durability and performance, their products are built to withstand the elements while providing powerful, high-quality audio for UTV enthusiasts. Whether on trails, dunes, or mud, MB Quart ensures you experience the best soundtrack for every offroad adventure.