MB QUART NA4-320.4-UOB Nautic Waterproof Channel Amplifier 806576238201 40X4 4OHM

( Brand: Mb Quart ), ( Manufacturer Part Number: NA4-320.4-UOB ), ( Part Type: Amplifier ), ( Bullet Point1: 320w Max 4-channel Class D Amplifier, 4 40w 4 ), ( Bullet Point2: Ip67-rated Waterproof And Dustproof Design With Fully Potted Inte ), ( Bullet Point3: Q-stasis Low-noise Preamp Circuit Improves Signal Clarity And Red ), ( Bullet Point4: Compact Chassis With Quick-connect Power, Speaker, And Rca Connec ), ( Bullet Point5: Fixed 80hz High-pass Crossover With Electronic Control For System ), ( Rms Power: 160 ), ( UPC: 806576238201 )

Review MB QUART Nautic 320 Watt Waterproof Channel Amplifier 40x4 4ohm

The **MB NA4-320.4-UOB Nautic 320 Waterproof Channel Amplifier** is a high-performance marine audio solution designed to deliver crystal-clear sound and robust reliability in the demanding environments of boats, yachts, and offshore vessels. Part of the premium **Nautic 320 series**, this **4-channel amplifier** combines cutting-edge technology with marine-grade durability, making it an ideal choice for audiophiles and marine enthusiasts who demand both power and precision. With a **400-watt RMS output per channel** into **4-ohm loads**, this amplifier ensures deep, dynamic bass and crisp highs, even at high volumes, without distortion or fatigue. Its **waterproof and dustproof** construction, rated to **IP67 standards**, ensures protection against saltwater corrosion, humidity, and harsh marine conditions, allowing it to operate seamlessly in the open air, on deck, or in enclosed cabins. The **NA4-320.4-UOB** features a **bridgeable design**, enabling it to be paired with another identical unit for a **stereo bridge configuration**, effectively doubling power output to **800 watts RMS per channel** when connected to a compatible receiver, making it versatile for both single and multi-zone marine audio setups.

Engineered with **high-efficiency Class-D amplification**, this amplifier delivers exceptional power efficiency while maintaining low heat output, reducing the need for excessive cooling and minimizing the risk of overheating in confined spaces. Its **wide operating temperature range** from **-20 C to 60 C** ensures consistent performance whether the vessel is cruising in tropical waters or navigating through icy northern seas. The **NA4-320.4-UOB** also incorporates **advanced protection features**, including **overload, short-circuit, and thermal protection**, safeguarding both the amplifier and connected speakers from damage due to electrical surges, moisture ingress, or improper wiring. Its **low-noise preamp outputs** allow for seamless integration with marine sound systems, enabling the connection of additional amplifiers, equalizers, or processing units for customized audio tuning.

Built with **marine-grade materials**, including **corrosion-resistant metal enclosures** and **waterproof connectors**, this amplifier is designed to withstand the rigors of saltwater exposure, vibration, and constant motion. The **compact yet rugged design** ensures easy installation in tight spaces, whether mounted beneath a seat, in a cabin, or on a bulkhead, while its **vented back panel** promotes efficient airflow, keeping internal temperatures stable even during prolonged use. The **NA4-320.4-UOB** also supports **remote control via RS-232 or IR**, allowing for easy integration with marine audio systems that require centralized management, such as those found in luxury yachts or commercial vessels. With its **high-current power supply** and **low impedance handling**, this amplifier is perfectly suited for driving **high-efficiency marine speakers**, including **subwoofers and full-range systems**, delivering powerful, immersive sound that enhances the onboard experience whether for entertainment, navigation alerts, or background music.

In summary, the **MB NA4-320.4-UOB Nautic 320 Waterproof Channel Amplifier** is a **high-end marine audio powerhouse** that merges **uncompromising performance, durability, and versatility** into a single, robust unit. Whether powering a **multi-zone stereo system, a high-fidelity sound setup, or a robust subwoofer configuration**, this amplifier ensures that every note, announcement, or melody is reproduced with **clarity, power, and reliability**, even in the most challenging marine environments. Ideal for **private yachts, fishing boats, commercial vessels, and adventure cruisers**, the **NA4-320.4-UOB** sets a new standard for marine audio amplification, blending **innovation, durability, and audiophile-grade sound** into a single, waterproof solution.

### Pros and Cons of buying a **MB NA4-320.4 (UOB NA4-320.4 / Nautic 320) Waterproof Channel Amplifier (40x4, 4 )**

The amplifier delivers **400 watts per channel at 4 ohms**, making it suitable for demanding setups with large speakers, subwoofers, or high-gain systems. This ensures strong bass response and clear sound reproduction even in open-air or marine environments.

The **IP67-rated enclosure** protects against dust, water, and harsh conditions, making it ideal for outdoor use, marine applications, or environments with high humidity. This durability extends the amplifier s lifespan and reduces maintenance needs.

The amplifier is designed for **low distortion and high fidelity**, ensuring clean amplification across a wide frequency range. It is often used in professional sound systems, car audio, and marine applications where sound integrity is critical.

It can be paired with **high-gain speakers, subwoofers, or active components** due to its robust power handling. The **4-channel configuration** allows for flexible wiring options, such as a **4x1 setup (one subwoofer and three tweeters) or a 2x2 setup (two subs and two tweeters)**.

As a product from **MB Components (now part of UOB or Nautic brands)**, it is known for **durability and long-term performance**. Many users report minimal issues if installed and maintained correctly.

Beyond marine use, it can be used in **outdoor events, car audio, home theater, or industrial sound systems** where waterproofing and high power are required.

The amplifier features **clear labeling, robust connectors, and a straightforward wiring diagram**, making it accessible for both beginners and experienced installers.

---

At **400W per channel**, the amplifier consumes significant electrical power. This may require a **heavy-duty power supply (e.g., 200A alternator in marine applications) or a dedicated circuit** to avoid voltage drops or system overload.

Operating at high power levels generates **significant heat**, which must be managed to prevent overheating. Proper **ventilation, cooling, and installation in a well-ventilated area** are essential to avoid thermal shutdowns.

The amplifier is **bulky and heavy**, which can be a drawback for **space-constrained installations** (e.g., small boats, compact cars, or tight enclosures). Additional mounting considerations may be needed.

High-power, waterproof amplifiers like this are **not cheap**. The price point may be prohibitive for **budget-conscious users** or those who only need moderate power.

In boats, **alternator voltage fluctuations** can occur, especially under load. A **voltage regulator or stabilizer** may be necessary to ensure consistent performance and prevent damage.

While many high-end amplifiers include **short-circuit, overload, and thermal protection**, some users report that **aggressive wiring or poor installation** can still lead to issues. Always check the **specific model s protection features**.

If paired with **cheap or poorly designed audio sources (e.g., weak amplifiers, noisy power supplies)**, the output may still suffer from **noise or distortion**, despite the amplifier s power.

---

The **MB NA4-320.4 (UOB NA4-320.4 / Nautic 320) is an excellent choice** for users who need a **high-power, waterproof amplifier** for demanding applications like marine sound systems, outdoor PA setups, or high-end car audio. Its **400W per channel output, rugged construction, and reliability** make it a strong performer in environments where durability and power are critical.

- Users with **limited power supply capacity** (may require a heavy-duty alternator or dedicated circuit).

- Those who need **compact or lightweight solutions** (due to size and weight).

- Budget-conscious buyers who can opt for lower-power alternatives.

If you **prioritize power, waterproofing, and long-term reliability** and can accommodate its requirements (cooling, wiring, and power supply), this amplifier is a **solid investment**. If you need **lower power, smaller size, or cost efficiency**, consider alternatives like **2-channel marine amplifiers or lower-wattage waterproof units**.

- **Buy if:** You need a **high-power, waterproof amplifier** for **marine, outdoor, or professional audio applications** and can ensure proper **cooling, wiring, and power supply**.

- **Avoid if:** You have **voltage instability issues, limited space, or a tight budget**.

- **Consider alternatives:** If you don t need **400W per channel**, a **2-channel marine amplifier (e.g., MB NA2-200.4)** or a **lower-wattage waterproof amp** may suffice.

- **Pair with:** A **high-quality power supply, proper cooling, and compatible speakers** to maximize performance.

Would you like recommendations on specific accessories (e.g., cooling solutions, wiring tips) for this amplifier?

Details:

Item Details Condition USED, Brand MB Quart, Weight 10.00 UPC That means more than selling gear it understanding system matching, power requirements, signal integration, real-world installation considerations, and the small details that determine whether a performs way should. Built to meet IP67 standards, the NA4-320.4 is fully waterproof and dustproof, ensuring dependable operation in wet harsh conditions. Marine Audio.

Integrated protection circuitry monitors thermal, overload, DC, and short conditions, providing peace of mind during extended use. This design significantly enhances long-term durability and system reliability where traditional amplifiers would fail. MB Quart NA4-320.4 Nautic 320 Watt Waterproof 4 Channel Amplifier 40x4 4OHM, 80x4 2OHM - Used, Open Box: Review details, highlights, and below. Designed with a compact footprint and rugged construction, this 4-channel Class amplifier produces 160 watts of RMS output, making it ideal for powering full-range speaker systems in outdoor vehicles.

Its potted internal circuitry provides an added layer of protection by sealing sensitive components against moisture, vibration, and corrosion. Installation is streamlined thanks to quick-connect power, speaker, and RCA terminals, along with nickel-plated, corrosion-resistant connections that maintain signal integrity over time. Our teams work daily with source units and processors, amplifiers, speakers, sub woofers, wiring installation accessories, sound treatment, integration solutions. The amplifier also features a highly efficient PWM MOSFET power supply with Simpatico coil design, maintaining stable voltage while reducing heat buildup.

part #: na43204 price

• $206.99

specifications caramplifieca:

• brand: Mb Quart
• mpn: Na4-320.4-uob
• part type: Amplifier
• bullet point1: 320w Max 4-channel Class D Amplifier, 4 40w 4
• bullet point2: Ip67-rated Waterproof And Dustproof Design With Fully Potted Inte
• bullet point3: Q-stasis Low-noise Preamp Circuit Improves Signal Clarity And Red
• bullet point4: Compact Chassis With Quick-connect Power, Speaker, And Rca Connec
• bullet point5: Fixed 80hz High-pass Crossover With Electronic Control For System
• rms power: 160
• upc: 806576238201

returns caramplifieca:

• policy: Returns Accepted
• method: Money back
• time: 30 Days
• paid by: Seller

general caramplifieca:

• Vehicle Electronics GPS > Car Audio > Car Amplifiers
• condition: Used

seller caramplifieca:

• rating: 99.8%
• # reviews: 35583
• city: Springfield, Missouri

shipping caramplifieca:

• class: Standard, Expedited, One-day
• cost: $0.00
• service: Standard, Expedited, Overnight
• type: Fixed
• transit: 5-5 Days

payments caramplifieca:

• credit card: Diners-club
• other
• wallet: Paypal

offer caramplifieca:

• availability: In Stock
• sold: 0
• started: April 9, 2026
• quantity: 1
• options: Ship-to-home

Mb Quart NA4-320.4 Is Similar To:

• Da1-1200.1 Hifonics Mb Quart Discus Amplifier Vehicle Electronics 731215384677 (27.4% similar) 38X16 anarchistic: 77. 1 discus amplifier 1200 watt mono. The discus series amplifiers offers an all new ground-up design with focused mass aluminum heat sinks...(March 23rd, 2018)
• Da1-2000.4 Hifonics Mb Quart Discus Amplifier 806576223924 (32.4% similar) PRODUCTFEATURES6. 25 anarchistic: 24. 2 POUNDSSIZE:4-CHANNEL 2000 -WATTITEMDIMENSIONS:3. 4 discus amplifier 2000 watt four channel...(April 16th, 2018)
• 08-2010 Dodge Ram Mb Quart 613815886839 (17.2% similar) This includes blown speakers with burned voice coils...(January 28th, 2018)
• Da1-2400.1 Mb Quart 2400 Watt 806576223955 (30.5% similar) Mb Quart DA1 400 watts x 1 chan. Focused mass aluminum heat sinks watt bass mono block discus car amplifier all new ground-up design ohms: 1,200 watts x 1 chan wide CBS provide better parts spacing ample extrusion length for high thermal performance three-stage protection circuits frequency ...(September 12th, 2017)
• Da1-3000.1 Mb Quart Mbquart Discus (24.4% similar) DA1 for sale is a new Mb Quart DA1-3000. 1 discus amplifier,class 1-CHANNEL 3000-WATT: Mb Quart...(January 10th, 2018)
• Da1-500.2 Mb Quart Channel Watt Amp Class Car Audio Stereo Amplifier (33.1% similar) Mb Quart 2 channel 500 watt a b class car audio stereo amplifier DA1-500. 2 power 1-OHMN a 2-OHMS2X250W 4-OHMS2X125W mono bridged 2-OHMSN 4-OHMS1X500W frequency RESPONSE10HZ-45KHZ signal to noise ratio 90DB Thad...(December 16th, 2018)
• Da1-600 Mb Quart 4 600w (23.2% similar) What is the history of item. Please see pictures. Has been tested and works well. What are your operating hours. Shipping carriers: sure post, ups USPS 1-6 day. Your satisfaction is our number one goal. 875, wi whats included. Of the time if its pictured included...(January 30th, 2018)
• Dsc15001d Mb Quart Car Amp (26.1% similar) Wouldn't sell it if didn't work. Dont have time for BS. Work likes new. Selling a like new Mb Quart mono. Puts out 1500 watts rms at 1 ohm...(April 9th, 2018)
• Dsc450 Mb Quart Channel Amplifier Old School Car Audio Nib Nos (38.4% similar) Bridged, 4 ohms: 200 watts x 2 chan. 2 ohms: 100 watts x 4 chan. See my other old school car audio sales going on now. 7H4-GAUGE power and ground wiring is required for installation. 2X25 fuses for high current power. Features series 4-CHANNEL class ab car power RATING:4 ohms: 50 watts x 4 ...(October 26th, 2018)
• Dsc480 Mb Quart Rab 450 4 Channel (39.3% similar) So I'm just trying to recoup a little of the money back. No box or manual...(February 26th, 2018)
• Fx1.500 Mb Quart Mono Block Class Ab Channel Car Audio Stereo (32% similar) 500 400W mono block class ab 1 channel car audio stereo amplifier. Mb Quart FX1...(December 16th, 2018)