The MTX Thunder4244 4-channel amplifier uses a "pure N-channel" design with a MOSFET power supply for impressive power and outstanding performance. This efficient circuitry turns most of the available energy into usable wattage, rather than the heat generated by most amps.

Intelligent Surface Mount Technology gives the amplifier superior resistance to vibration, for long-term reliability. Speaker-level inputs feature SmartEngage, which turns the amp on when it gets signal from the receiver.

  • 2-, 3-, or 4-channel output
  • Tri-way capable (Tri-Way crossover required)
  • 60 watts x 4 at 2 ohms
  • 120 watts x 2 in bridged mode
  • requires 4-gauge power and ground leads — wiring and hardware not included with amplifier
  • PWM MOSFET switching power supply
  • Intelligent Surface Mount Technology for cleaner sound
  • front selectable 85 Hz high-pass crossover, 18 dB/octave
  • rear selectable 85 Hz high-pass/low-pass crossover, 18 dB/octave
  • preamp outputs
  • speaker-level inputs with SmartEngage (turns the amp on when it detects signal from the receiver, eliminating the need for a separate turn-on lead from your receiver)
  • 9-5/16"W x 2-1/8"H x 11-1/2"D
  • 1-year warranty

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Hands-on research

What's in the box?

Download owner's manual

  • Black MTX Thunder 4244 amplifier with chrome trim
  • Two 25-amp blade fuses (installed)
  • 2 Speaker level input wiring harnesses
  • Warranty registration and customer survey
  • Performance certificate
  • Owner's manual (English/French/Spanish/German)
  • Input/Output Connections sheet
  • MTX Audio sticker
  • Bridged impedance warning sticker.

Product Research

Inputs, Outputs and Controls


Class A 100% Discrete Driver Circuitry Topology: The preamp stages use Class A topology for low distortion and a high damping factor; the result is tight, controlled bass.

Pure N-Channel Design: The pure N-channel design is more linear than typical N-Channel designs, so the speaker you connect to the amplifier will be better controlled. The signal travels through fewer parts so the signal-to-noise ratio is enhanced, the power rating is better, and the amp runs louder, longer.

Smart-Engage™: When using the speaker-level input, the amp automatically turns on when it senses signal from the head unit, eliminating the need for a remote turn-on connection. In many cases, this feature will allow you to install the amplifier without the need to remove your radio.

Internal Crossovers: There is one crossover for the front channels and another for the rear channels. The crossover for the front channels may be set for 85Hz, 18dB/octave high-pass operation, or it may be turned off for full-range operation. The crossover for the rear channels may be set for 85Hz, 18dB/octave high- or low-pass operation, or it may be turned off for full-range operation.

Buffered, Isolated RCA Output: In addition to the front and rear sets of preamp inputs, there is a set of full-range summed RCA preamp outputs. The outputs allow you to daisy-chain one amplifier to another.

Intelligent Surface Mount Technology: Features substantially shorter internal and external lead lengths, reducing stray capacitance and inductance, which results in cleaner and more accurate musical reproduction with less noise interference.

Real-time Computerized Protection Circuit: The protection circuit makes sure you amp is operating within safe parameters for maximum power and protection.

Acoustically Seamless Turn-on/Turn-off: A circuit that prevents turn-on/turn-off "thump" is included to eliminate turn-on/off noise.

Iso-Feet™: Four rubber Iso-Feet are attached to the amplifier. The rubber feet let you mount the amp securely, while preventing the mounting screws from coming into contact with the amp's chassis; this helps prevent ground loops.

Terminals: The terminals are nickel-plated, heavy-duty screw terminal connectors.

Performance Certificate: MTX tests each amplifier, and the technician records the "actual" power output on the Certified Performance Certificate included with each amp. The amp must meet or exceed the rated specification in order to leave the factory.

Inputs, Outputs and Controls

Left Side of the Amplifier

  • Front and Rear Variable Gain Controls: the gain controls allow you match the input sensitivity of the amp to the particular source unit you are using
  • RCA Input Select Switch: a switch used to match the amp's input to the source unit's output so all four channels of the amp are driven. If your source unit has 2 outputs (a left and a right), connect them to the amp's front channel inputs, and place the input select switch in the 2CH position. Likewise, if you are using a 4-channel source, place the input select switch in the 4CH position. In the 4CH position, the fader on your source unit will operate.
  • Front left and right RCA input jacks
  • Rear left and right RCA input jacks
  • RCA Sum Out Jacks: RCA preamp output jacks, which allow you pass summed, full-range signals from this amplifier to another amp in a daisy-chain configuration
  • Front Crossover Switch: lets you select high pass or full range operation
  • Rear Crossover Switch: lets you select high pass, low pass, or full range operation
  • Front and Rear Speaker Level Inputs: two 4-pin inputs for use with the included speaker-level input harnesses; allow the amp to operate with source units that do not have preamp outputs

Right Side of the Amplifier

  • Speaker Outputs: these terminals are configured like steps, with the rear left and right outputs in a row below the front left and right outputs (0.34" wide)
  • BATT (power): screw terminal (terminal is 0.54" wide)
  • GND (ground): screw terminal (terminal is 0.54" wide)
  • REM (remote turn-on): screw terminal (terminal is 0.34" wide)
  • Fuses: slots for two 25-amp blade fuses (fuses are included)

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team — they open the box, verify contents, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

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Get everything you’ll need to enjoy your new MTX Thunder4244

Patch cables take the music from your stereo to the amplifier. Most amp wiring kits don't include them.
EFX 2-Channel RCA Patch Cables

EFX 2-Channel RCA Patch Cables

Core Series Twisted RCA patch cables — available in 5 different lengths (6-foot)

Item #: 142RCT6B

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EFX 2-Channel RCA Patch Cables

EFX 2-Channel RCA Patch Cables

Reference Series Multi-Core RCA patch cables — available in 5 different lengths (12-foot)

Item #: 142RR12

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EFX 2-Channel RCA Patch Cables

EFX 2-Channel RCA Patch Cables

Elite Series Braided Multi-Core RCA patch cables — available in 5 different lengths (3-foot)

Item #: 142RE3

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T-Spec 2-Channel RCA Patch Cables

T-Spec 2-Channel RCA Patch Cables

Available in 7 different lengths (10-foot)

Item #: 120RCA102


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