If you're really serious about your bass, check out the Big Kahuna — the MTX Thunder81000D mono subwoofer amplifier. MTX uses its ultra-efficient Adaptive Class D amp technology to get 500 watts of kickin' power out of a relatively small package. The built-in compression circuit irons out voltage peaks so you can push this amp hard without damaging your subs.

The Thunder81000D is loaded with the best of MTX's innovative technology, including super-fast MOSFET power supplies, low-impedance/high-power transformers (which produce less heat for more reliable performance), and a variable low-pass crossover with a sharp 24 dB per octave slope.

Add Thunder EQ bass boost and an EBC2 port (which allows control of multiple Thunder EQ-equipped amps with one EBC remote), and you'll have the biggest, baddest bass output machine around!

Important Note: Because of this amp's 150-amp fuse rating, a pre-packaged wiring kit cannot be used for installation — see the "Wiring Recommendations" section in "Detailed Info."

  • 500 watts RMS x 1 at 4 ohms
  • 1000 watts x 1 at 2 ohms
  • variable 40-200 Hz low-pass crossover, 24 dB/octave
  • preamp outputs for daisy-chaining amplifiers
  • PWM MOSFET switching power supply
  • Thunder EQ bass boost (up to 18 dB at 40 Hz)
  • compression circuitry guards against damaging speakers during loud musical passages at high sound-pressure levels
  • EBC2 port
  • 17-13/16"W x 2-1/4"H x 9-7/8"D
  • 1-year warranty

Hands-on research

What's in the box?

Download owner's manual

  • Black MTX Thunder 81000D amplifier with chrome trim
  • Power and Ground terminal set screws (inside the Owner's manual)
  • Warranty registration and customer survey card
  • Performance certificate
  • Owner's manual (English/French/Spanish/German)
  • Amplifier Input/Output Connections sheet
  • MTX Audio sticker
  • Impedance warning sticker (on bag).

Product Research

Inputs, Outputs, & Controls
Wiring Recommendations


Patented PWM MOSFET Switching Power Supply:  This type of power supply is used for maximum power output and protection.

Adaptive Class D Technology: While typical Class D amps tend to generate high frequency energy that must be filtered to prevent harmonic interference in the FM radio frequency range, Adaptive Class D Technology directs the amp's switching energy away from FM radio ranges as the amp's load and output increases. This improves the amp's overall signal-to-noise ratio and eliminates interference generated by more common Class D amps.

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.

Low Impedance, High Power Transformers: These provide more power and produce less heat.

Defeatable Compression Circuit: This is a new feature that prevents clipping even at high SPL levels and protects the speakers against potential damage at high volumes. It is switchable for those SPL competitors who may run their amplifiers into clipping intentionally. Note: Damage to speakers may occur when the Compression Circuit is "off".

Real-time Computerized Protection Circuit: The protection circuit makes sure your 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.

Rubber Insulated Iso-FeetT: 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.

Buffered, Isolated RCA Outputs: In addition to the set of preamp inputs, there is a set of full-range RCA preamp outputs. The outputs allow you to daisy-chain one amplifier to another. Also, the RCA output jacks allow for multiple bass amplifiers to be level controlled using one EBC (sold separately).

EBC (Electronic Bass Control) 2: This amplifier includes an Electronic Bass Control Port that will accept the cable from an optional EBC. When an EBC is connected, you have access to an additional 3dB of gain and 23dB of attenuation from the driver's seat. If the optional EBC is installed, the bass level will be able to be adjusted to overcome noise and other interference. With EBC 2, multiple compatible amps can be controlled.

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.

Thunder EQ: Thunder EQ is a continuously variable Bass Boost (0-18dB) centered at 40Hz. 

Crossover: This amplifier includes a 24dB/octave, low-pass crossover that is always active. There is a crossover frequency control, continuously variable from 40Hz to 200Hz, that allows you to dial in the low-pass cut-off frequency of your choice. 

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.


Peak (Dynamic) Power (measured at 14.4 Volts DC):  
  • 850 Watts x 1 into 4 Ohms
  • 1500 Watts x 1 into 2 Ohms

Inputs, Outputs, & Controls

Left Side:

  • Gain Control: allows you to match the input sensitivity of the amplifier to the particular source unit you are using
  • Thunder EQ Control: a rotary control that allows you to set the bass boost applied to the speaker output signals 
  • Frequency Control: a rotary control that allows you to select a low-pass crossover frequency from 40Hz to 200Hz
  • Left and Right RCA Input Jacks
  • Left and Right RCA Output Jacks: RCA preamp output jacks, which allow you pass full-range signals from this amplifier to another amp in a daisy-chain configuration
  • EBC Port: this is a phone-style jack made to accept the cable from and optional EBC (Electronic Bass Control) 

Right Side:

  • Power Terminal: set screw terminal designed to accept cables as large as 1/0 gauge
  • Ground Terminal set screw terminal designed to accept cables as large as 1/0 gauge
  • Remote Turn-on Terminal: (0.34" wide) 
  • Speaker Terminals: (0.34" wide) there are two +/- pairs of terminals, but they are connected together internally and they provide mono output; if two 4-ohm speakers are connected, one to each set of terminals, the amplifier will see a 2-ohm load, because the terminals are internally connected, in parallel with each other

Wiring Recommendations

Wiring Recommendations: This amplifier requires a 150-amp fuse, so its fuse rating exceeds that of stock wiring kits. Since pre-packaged amplifier wiring kits cannot be used, you must purchase all the necessary items separately. The separate parts and wiring needed to install this amplifier are as follows:

  • One ANL wafer-style fuse holder capable of accepting 1/0 gauge wire
  • One 150 amp ANL wafer fuse
  • 2 power rings for 1/0 gauge cable
  • 1/0 gauge power cable (to connect the battery to a fuse holder and the fuse holder to the amplifier)
  • 1/0 gauge ground cable 
  • Remote turn-on cable (speaker wire can be used as remote turn-on cable)
  • One set of stereo RCA patch cables
  • Speaker wire

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.

MTX Thunder81000D Reviews

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great amp

Written By brandon, grants pass oregon on Saturday, September 21, 2013

This amp slams. Makes every sub I have sound way better.

Pros: Loud bass, looks cool, rubber mounts

Cons: Not 1 ohm stable. Very big and heavy.

Amazing Amp!

Written By Danny, Seattle,Wa on Sunday, November 01, 2009

I recently got this amp and WOW this is a monster of a amp. I love it! I have this amp Running a single DVC 18" and it really slams. If you can get this amp DO IT!

Get everything you’ll need to enjoy your new MTX Thunder81000D

Don't forget the patch cords You'll need patch cords to get the signal from your receiver to your new amp, and the wiring kit doesn't include any.
T-Spec 2-Channel RCA Patch Cables

T-Spec 2-Channel RCA Patch Cables

Available in 7 different lengths (17-foot)

Item #: 120RCA172


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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 (17-foot)

Item #: 142RR17

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