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4-channel marine amplifier — 75 watts RMS x 4 at 4 ohms

Item # 236WET754

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About the MTX WET75.4

MTX gets WET

MTX brings their years of land-based experience to the water with their WET Series marine components. Based on their Thunder Series amps, the WET75.4 4-channel amplifier is designed to power your speakers under seriously adverse conditions. Its weather-resistant features include a conformal coated circuit board, stainless steel hardware, rubber gaskets around the RCA connectors, and plastic control covers to keep moisture from getting to the amplifier. The 75.4 also features MTX's surface mount technology, which attaches critical components directly to the circuit board to minimize the effect of vibration.

MTX WET75.4 100W x 4 Marine Amplifier

MTX built this rugged amp to stand up to moisture, salt, and sun.

Power and control

Behind the weatherproofing and the construction, you'll find a Class A/B 4-channel amplifier capable of delivering 75 watts per channel at 4 ohms, or 100 watts at 2 ohms. Variable high-pass filters on the front and rear outputs, along with a variable low-pass filter on the rear outputs, allow you to fine-tune the sound environment. And MTX made this amp to fit the tight spaces in a boat, with a small footprint that allows it to go almost anywhere and an extruded heat sink that'll keep things cool. It's ready to make waves. Are you?

Product highlights:

  • 4-channel marine amplifier
  • Class A/B design
  • 75 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
  • variable high-pass filters on front and rear outputs
  • variable low-pass filter on rear outputs
  • conformal-coated circuit board
  • weather-resistant construction
  • dimensions: 12-1/8"W x 6-3/8"D x 2-1/4"H
  • warranty: 2 years
  • Our 60-day money-back guarantee
  • MFR # WET75.4

What's in the box:

  • 4-Channel amplifier
  • 4mm Allen wrench
  • 2mm Allen wrench
  • Four 5/8" Stainless steel self-tapping screws
  • Owner's manual (English/ Spanish/ Portuguese/ French)

Customer reviews

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MTX WET75.4 Reviews

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Overview: The MTX WET75.4 is a full range 4-channel amplifier designed for the harsh marine environment. The amp features a conformal coated PCB, covered controls, rubber gaskets around the RCA inputs, and stainless steel mounting hardware. The output power is 75 watts RMS x 4 at 4Ω, 100 watts RMS x 4 at 2Ω, and 200 watts RMS x 2 bridged at 4Ω.

Note: The cover over the gain and crossover controls is held in place by two 2.5mm Allen head screws; no 2.5mm Allen wrench is included with the amp.

Gain: The amp's front and rear channel rotary gain controls are independent and continuously variable from 200mV to 5V to match the output of the source unit.

Protection Circuits: The WET75.4 provides protection against overheating, under/over voltage, and electrical short circuits.

Crossovers: The front and rear channels have independent built-in crossovers:

  • Front: high-pass; continuously variable from 10 Hz (full range) to 200 Hz
  • Rear: switchable between low-pass, full range, and high-pass; the crossover point (high-pass or low-pass) is continuously variable from 50 Hz to 750 Hz


Power Terminals: The WET75.4 features set screw terminals for power, ground and remote turn-on. The power and ground terminals will accommodate up to 4 AWG wire, while the remote turn-on terminal will accept up to 10 AWG wire. The set screws are loosened/tightened with the supplied Allen wrenches. MTX recommends the use of 4 AWG power and ground wires.

Note: The Amplifier is not equipped with an internal fuse. An external 60-amp fuse (not included) must be installed on the power wire. If the system has only this amp and a wiring kit is used that includes a fuse with a value other than 60-amps, the original should be replaced with a 60-amp fuse.

Speaker Connections: The amplifier is equipped with four pair of set screw terminal speaker outputs. Each terminal will accommodate up to 10 AWG bare wire and is loosened/tightened with the supplied Allen wrench.

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Customer Q&A

Crutchfield asked: Why did you buy this?
recommended by Tyler [ James  Jun 26, 2017 ]

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