MB Quart - NA4-400.2 Nautic 400 Watt Waterproof 2-Channel Amplifier 100x2 @ 4OHM, 200x2 @ 2OHM - Black/Gray

The MB Quart NA4-400.2 Nautic is a compact 2-channel amplifier engineered for reliable, high-output performance in marine and powersports environments. Built around a highly efficient Class D topology, it delivers up to 400 watts of total power while maintaining a small footprint that fits easily into tight installation spaces. Designed for harsh conditions, the amplifier features IP67-rated protection along with fully potted internals. This sealing process protects critical components from water, dust, vibration, and corrosion, making it ideal for boats, UTVs, and other outdoor applications where durability is critical. An aluminum heatsink further improves thermal management, allowing the amplifier to perform consistently under load. On the audio side, MB Quart’s Q-Stasis low-noise preamp circuit helps reduce incoming signal noise, improving clarity across the entire frequency range. With a response of 6Hz to 29kHz and a signal-to-noise ratio greater than 105 dB, the NA4-400.2 is capable of clean, full-range sound reproduction. Variable high-pass and low-pass crossovers (12 dB/octave) provide flexible tuning, making it easy to dial in performance for a wide range of speaker setups. Installation is streamlined with quick-connect power, speaker, and RCA terminals, along with corrosion-resistant nickel-plated connections. Integrated protection circuitry monitors thermal, overload, DC, and speaker faults, with LED indicators for system diagnostics. Specifications Model: NA4-400.2 Channels: 2 Amplifier Class: Class D (Full Range) Max Power: 400W Power @ 4 Ohms: 2 x 100W Power @ 2 Ohms: 2 x 200W Frequency Response: 6Hz – 29kHz Signal to Noise Ratio: >105 dB Total Harmonic Distortion (THD): 1.0% High Pass Crossover: 15Hz – 300Hz (12 dB/Octave) Low Pass Crossover: 50Hz – 300Hz (12 dB/Octave) Input Sensitivity: 0.2V – 9V IP Rating: IP67 Fuse Rating: 30A x 1