Description
Compact Marine-Grade Mono Amplifier
The MB Quart NA4-400.1 Nautic amplifier is a compact, high-efficiency mono amplifier designed for marine and powersports applications. Built to deliver reliable subwoofer power in harsh environments, it combines durable construction with consistent performance in a small footprint.
With 400 watts of maximum output and a highly efficient Class D topology, this amplifier is ideal for systems where space is limited but dependable bass output is required.
Marine-Grade Protection
Engineered to meet or exceed IP67 standards, the NA4-400.1 is fully protected against water and dust intrusion. Its potted internal design seals critical components, preventing moisture-related damage such as corrosion or short circuits.
This rugged construction makes it suitable for boats, UTVs, motorcycles, and other exposed environments.
Performance & Signal Control
- Mono amplifier configuration for subwoofer applications
- Variable low-pass crossover: 50Hz–150Hz (12 dB/octave)
- Adjustable subsonic filter: 15Hz–50Hz
- Bass boost: 0–12 dB
- Input sensitivity: 0.2V–9V
- Signal-to-noise ratio greater than 100 dB
The integrated Q-Stasis preamplifier circuit minimizes noise from incoming signals, improving overall sound clarity.
Advanced Engineering
Utilizing a PWM MOSFET power supply and Simpatico coil design, the amplifier maintains stable voltage and efficient power delivery. The aluminum heatsink helps dissipate heat quickly, supporting consistent operation even under demanding conditions.
Its full-range Class D design ensures high efficiency while keeping size and heat generation to a minimum.
Installation & Connectivity
Designed for convenience, the amplifier features quick-release connectors for power, speaker, and RCA inputs, making installation and removal simple. Nickel-plated connections provide corrosion resistance and long-term reliability.
A wired bass remote is included, allowing easy adjustment of output levels from a convenient location within the vehicle.
Protection & Diagnostics
Integrated protection circuitry monitors thermal conditions, overload, DC offset, and speaker shorts. LED indicators on the amplifier provide real-time diagnostic feedback for system status and protection events.
Specifications
| Model | NA4-400.1 |
| Series | Nautic |
| Amplifier Type | Mono |
| Amplifier Class | Class D (Full Range) |
| Max Power | 400 watts |
| Power @ 2 Ohms | 1 x 400 watts |
| Power @ 4 Ohms | 1 x 200 watts |
| Frequency Response | 17Hz–165Hz |
| Signal-to-Noise Ratio | > 100 dB |
| Total Harmonic Distortion | 1.0% |
| Low Pass Crossover | 50Hz–150Hz |
| Subsonic Filter | 15Hz–50Hz |
| Bass Boost | 0–12 dB |
| Input Sensitivity | 0.2V–9V |
| IP Rating | IP67 |
| Fusing | 30A x 1 |
Used Frequently Asked Questions
- What does used mean? Used products may be unused customer returns that are essentially "new" items, or they may be previously installed products that were returned under warranty or during our return policy period.
- What is the warranty? All of our used items come with a 90-day warranty.
- What's it look like? All of our used items are inspected and graded by our returns team at our facilities. They will test them and grade them to one of four standard gradings: Used Open Box, Used Very Good, Used Good, and Used Acceptable. Please see the following descriptions of each grade - also note that if an item falls under ANY of the criteria for a certain grade, even though the rest of the product is better, we will give it the lowest grade.
- Used Open Box An item in perfect working condition. Original protective wrapping may be missing, but the original packaging is intact and in good condition with minor damage possible. Instructions are included.
- Used Very Good A well-cared-for item with limited use, remains in good working condition. The item may show some limited signs of wear,small scratches,cosmetic blemishes. Item may arrive with damaged packaging or be repackaged and could be missing some accessories.
- Used Good The item shows wear from use, remains in good condition and functions properly. May have damaged packaging or be repackaged. It may be marked, have identifying markings on it, have minor cosmetic damage. It may be missing some parts or accessories.
- Used Acceptable The item is fairly worn but continues to function properly. While repackaged; signs of wear can include aesthetic issues; scratches, dents. The item may have markings on it or show signs of previous use. Item may be missing some parts or accessories.
- Have more questions? Call us, send us a chat, or an email. We'll be able to answer any additional questions you may have.