Skip Navigation


4-channel car amplifier — 75 watts RMS x 4

Item #: 236THND754

In Stock

21 Reviews | 1 question - 1 answer

Your price: $199.99 Earn up to 200 Rewards points

Add to Cart

+ Add to wishlist + Email me alerts for this product

Open Box: $179.99

View all associated offers

Upgrade your power for better sound

You'll get some serious MTX musical mojo when you put the MTX THUNDER75.4 4-channel amp in your car. This compact amp will drive each of your front and rear speakers with 75 watts RMS of detail-enhancing musical power. Install a nice set of speakers, and you'll hear sounds you've never heard before, even in your favorite songs. And this little bruiser will truly fit in places where amps don't usually go


You can also put this amp into 2-channel mode to drive two subwoofers with 200 watts RMS per channel. In 3-channel mode, you can run some nice components up front with two channels while running a sub off the third channel.

Advanced tone control

The crossover filters on the front and rear channels allow you to adjust the sound to your setup. The front channels use a variable high-pass filter to keep the bass away from your full-range speakers, so they play cleanly. The variable rear crossover can be set to high- or low-pass depending on whether you're running a subwoofer or full-range speakers on the rear amp channels. It also features a very wide range of crossover points, that'll be useful for tuning midrange and midbass speakers.

MTX THUNDER75.4 control panel

MTX THUNDER75.4 control panel

Product Highlights:

  • 4-channel car amplifier
  • 75 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
  • 200 watts RMS x 2 bridged at 4 ohms (4-ohm stable in bridged mode)
  • frequency response: 15-25,000 Hz
  • Class AB amp technology
  • variable high-pass filter on front channels (10-200 Hz, 12 dB/octave)
  • variable high- and low-pass filters on rear channels (50-750 Hz, 12 dB/octave)
  • preamp inputs
  • 4-gauge power and ground leads and a 60-amp fuse recommended — wiring and hardware not included with amplifier
  • no onboard fuses — when installing multiple amps in a system, an additional 60-amp in-line fuse between the distribution block and the amplifier is recommended
  • 12-5/8"W x 2-1/4"H x 6-5/16"D
  • warranty: 5 years (free repair or replacement for 2 years; prorated replacement for years 3 through 5)
  • Our 60-day money-back guarantee

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.

MTX THUNDER75.4 Reviews

Average Customer Review:

21 Reviews

Great product

Written by: Jacob C from Pflugerville, tx on November 22, 2015

Crutchfield Customer Review (What's this?)

Wired Amp to power two door speakers and a sub. It sounded great until I had to rearrange the wires to clean it up a bit and then the remote turn on wire came out. Stopped working after that so it must have been faulty. Contacted Crutchfield and they sent me a new one that works flawlessly. Powers my system with ease.



2008 Tahoe

Written by: Anonymous from New York on October 25, 2015

Crutchfield Customer Review (What's this?)

Excellent amp. Have it paired with a Pioneer AVIC 500NEX, connected to a pair of Hertz Hi-energy at front and bridged to an enclosed Kicker sub at the rear channel.


Cons: None

MTX 4 channel 75 amp/alpine HU

Written by: Farooq from Chicago on August 3, 2015

Crutchfield Customer Review (What's this?)

Sweet 4 channel amp for your highs and mids. I got it pushing 8 4 ohm speakers on a 2 ohm load per channel. My car, a crown Vic I have installed a ten speaker system with 2 15" kicker subwoofers.

Pros: Everything

Cons: Nothing

Dynamite in small pkg

Written by: Joe from Berry, Ky on May 18, 2015

Crutchfield Customer Review (What's this?)

It does get warm pushing 4 two-ohm loudspeakers with 100RMS, but without a problem. I like the MTX amplifiers they are hard workers, underrated on power output. Very satisfied. high recommendation.

Pros: Power and reproduction are great. it is not big, heavy, does a very good job. Happy,

Cons: None


Written by: Anonymous from Fayetteville, AR on March 27, 2015

Crutchfield Customer Review (What's this?)

Beautiful amp, smooth draw, and clear sound.



Awesome Amp for the money.

Written by: David from 33708 on March 19, 2015

Crutchfield Customer Review (What's this?)

Reasonably priced 4 channel amplifier with plenty of power. Driving 2 - 4Ohm 10" Subs in a band pass enclosure along with 2 - 6x9's. I'm not utilizing the built in cross over as I'm using an old Nakamichi EC200 to control frequencies & input levels

Pros: Good bump for the buck. Easy hookup & better than average warranty. I used this amp to replace an ADS PQ10 & P120. Better than anticipated results

Cons: A fan could be used in this amp when using it in subtropical environments. It runs a bit warm, almost hot to the touch when cranking it up for a while. Although it has not shut down due to thermal issues

Great amp for the price.

Written by: Chris from League city TX on January 8, 2015

Crutchfield Customer Review (What's this?)

Great amp for running components. Plenty of power.

Pros: Not too big. Plenty of power.

Cons: None

Sold unit

Written by: Dan from Elmira new york on January 5, 2015

Crutchfield Customer Review (What's this?)

Great clean power out of a reasonably small unit. I installed it by my self in a 2007 tacoma 4 door. This was my first install and I paired it up with a set of kicker 40css component front door speakers, 40cs rear door speakers, and a pioneer head unit. It was simple to install and tune. Thanks to the folks at Crutchfield any question I had was answered completely in a timely fashion. Will continue to do business with them as long as they are in business.

Pros: Clean sound Good user Manuel Great looks Easy tuning Great build quality

Cons: None found yet!


Written by: eace671 from Guam on December 9, 2014

Crutchfield Customer Review (What's this?)

Infinity 6030 component speaker sound great paired with this amp. Definitely going to buy this amp for my other vehicles. I would suggest breaking the amp in first before cranking it up. When first installed it did cut out at times.

Pros: Flexible tuning.

Cons: It gets a little hot.


Written by: Stevet from Mankato, MN on April 17, 2014

Crutchfield Customer Review (What's this?)

Great AMP. Not much to say... MTX amps are always stable and provide great, clean power.

Pros: Clean power

Cons: None

Small and powerful

Written by: Brian from Atlanta on December 28, 2013

Crutchfield Customer Review (What's this?)

This amp is pretty good at increasing the overall volume of you aftermarket stereo. It's not very detailed so any nuances that you are hearing on a decent home setup will not be revealed here with this amp, but for the money spent it sure gets my four component speakers loud enough to hear my stereo over road noise and my V8 growl.

Pros: Very small footprint considering the amps I've used in the past.

Cons: Speaker inputs are sort of crowded and require you to start with the bottom rows first of your speaker wire will be blocking the rear channel inputs.


Written by: Anonymous from Sarasota Fl. on October 13, 2013

Crutchfield Customer Review (What's this?)

Great amp for the price. Plenty of power and headroom for cranking. Compact for difficult mounting locations. Enough power for doors and a small sub.




Written by: Anonymous from eastland tx on July 29, 2013

Crutchfield Customer Review (What's this?)

Great product

Pros: I have had this amp running my door speakers and my sub and it never overheated I now just have it running my kick panels and front door components and it is more than I expected well wort every penny. Never distorts with proper adnustments .

Cons: make sure you set the gains properly its very sensitive.


Written by: Kram from Hawaii on July 3, 2013

Crutchfield Customer Review (What's this?)

This is a rock solid amp for its size. Powering kenwood 6.75 comp and 6.5 coaxials. Amazing sound and clarity.

Pros: Power for power Small size


Good Amp

Written by: low rider38 from Bethel, NY on June 21, 2013

Crutchfield Customer Review (What's this?)

This is a good solid amp. It gives all the power I need to my aftermarket interior speakers. It is very versatile in the way you have a high pass filter on front channel and option for high or low pass filter on rear channels. This gives you the option to power interior speakers on front channel and subs on the rear. The only thing I dont like about that is on the rear channel it is unclear exactly were the filter is set. The dial goes from 50 to 750 hrz, with no measurments inbetween. This makes you guess about were your setting the filter. Not a big deal but it bugs me a little. The only other downside is this amp does get hot, it does have a saftey shut off at a certain temperature. I have cranked my stereo on hot days for a period of time and it didnt shut off but did get very hot. Hot enough were I could only put my hand on it for a second without getting burned. Although my sub amp gets just as hot if not a little hotter and for that reason I give the amp a decent rating.

Pros: good power, sound quality, versatility

Cons: gets hot, filters on rear channels are not exact and have to be approximated.

MTX for the win!

Written by: Gyakusetsu from Denver, CO on June 17, 2013

Crutchfield Customer Review (What's this?)

Great little amp. Definitely provides a lot of power compared to any normal head unit. Very clean sound and super easy to install + tune. Built in HPF/LPF are very useful. This is a pretty simple piece of technology, but it is very well built and great at what it does. Bright blue LED indicator looks sweet under my seat, too! This amp gets my speakers going louder than I can stand without any distortion. My car is now the best ghettoblaster at any party!

I had an issue with the front HPF knob. It came defective and was not attached so it didn't actually do anything. Rather than void the warranty by trying to open the unit and maybe fix it, I went for an RMA Replacement. Crutchfiend's support/RMA process made it so that I wasn't without my amp for a week... which would've definitely left me without music in my car for some time. This company is great and easy to deal with!

Pros: Easy to install, looks great, nice and powerful without being overkill, great service, mostly well constructed

Cons: Large; tricky to find a spot where this guy can fit without being in the way. Luckily barely fit under my driver's seat. HPF knob issue. No fuse.


Written by: John H from Huntington Beach, Ca on June 9, 2013

Crutchfield Customer Review (What's this?)

Absolutely incredible!!!!! I recently installed the Pioneer AVH-X5500BHS with Polk DB6501 and DB651S in my 2006 Tundra DC. I initially tried to re-use the JBL amplifier. WHAT A MAJOR MISTAKE. I was soooo bummed with the quality of sound. The customer support at Crutchfield was awesome and immediately recommended this MTX 800W 4Channel amplifier. I AM ABSOLUTELY STOKED with the quality of sound. Thank you Crutchfield!!

Pros: Everything

Cons: Nothig

MTX Thunder Review

Written by: DJSteel from Lakeland, FL on June 6, 2013

Crutchfield Customer Review (What's this?)

Phenomenal amp for the price. I have it driving Kenwood 6.5 in the front and 6x9 in the rear. I didn't spend very much on the overall system, but what great sound provided by the amp. Very clean and clear power. I recommend this to anyone on a budget looking for good sound quality. I have never been disappointed with or by MTX.

Pros: Easy Setup, clean power, solid adjustments for the low price

Cons: I really don't have any cons for this amp. My expectation were met by an amp of this price.


Written by: R. Williams from Las Vegas NV on May 21, 2013

Crutchfield Customer Review (What's this?)

This is my first ever 4 channel amp. I am not sure what I was expecting, superior sound quality compared to the head unit's amp I guess. I have this amp running 4 new Pioneer 6.5" something or others. I don't think I like the speakers too much but the amp runs clean. There is no hiss and the speakers do come alive. So far no distortion. I do not have the gains turned up very high but the sound can get very loud. My kids don't like how loud it gets so that's good, right?

I am not sure that I needed this amp but I don't know, I haven't run the speakers from the deck, ever, so I can't compare. It all sounds like a stereo system should sound, I guess, all very normal.

Pros: Good price and good dependable brand.

Cons: none

Reviews for the MTX THUNDER75.4

Written by: Ivan from Puerto Rico on May 17, 2013

Crutchfield Customer Review (What's this?)

MTX never fails, small enough to put under the seat , my components never sounded better

Pros: good power, small footprint

Cons: none

Bulldog Amp

Written by: Anonymous from Denver, CO on March 22, 2013

Crutchfield Customer Review (What's this?)

Just replaced my older Sony 240W rms 4 channel amp because I wanted more intensity to match my sub amp / dual 12" sub 500W rms combo. The old Sony would totally distort before it could ever compliment my subs, so I wanted something better. Due to the price and output performance associated with this MTX, I took a gamble and tried it out without any customer reviews anywhere (new product and all). Winner winner chicken dinner! Sounds waaaay better than the old amp and goes way louder without any harshness/distortion. I currently have mine pushing two 5.25" Kickers in the front and two 6x9" Infinity reference speakers in the back, and it sounds leaps and bounds better than what I had before. I can't believe how small this is compared to my old amp, as it puts out more clean power than my old amp with maybe 1/3 the footprint. Install was easy and everything feels very solid with this amp. Two Issues: 1) the images currently on Crutchfield (as of 3/22/13) do not match what you get; that is an old MTX enclosure, and the new one looks better. I knew this before I purchased, not that it matters since it's hidden for me. 2) Now I want to update my sub amp and subs, as they now sound inferior. It's not that this amp is a superb audiophile amp or anything, but it sounds very clear to me compared to what I have owned before, and it has made me want more out of what I use to think was the heart of my system.

Pros: Good power for size and price, clean, neutral, easy install

Cons: If I find any, I will update this review

Crutchfield response on March 26, 2013 Thanks for your review. We've updated the picture.

Hands-on research

What's in the box?

Download owner's manual

  • 4-Channel amplifier
  • 4mm Allen wrench
  • 2mm Allen wrench
  • Four 1/2" Self-tapping screws
  • Owner's manual (English/ Spanish/ Portuguese/ French)

Product Research



Overview: The MTX Thunder75.4 is a full range 4-channel amplifier. It has aluminum heatsinks to dissipate heat generated by the amplifier. The amp produces 75 watts RMS x 4 at 4Ω, 100 watts RMS x 4 at 2Ω, and 200 watts RMS x 2 bridged at 4Ω.

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 Thunder75.4 provides protection against overheating, under 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 Thunder75.4 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.


5 Year Warranty Terms: MTX products purchased on or after January 1st, 2013 carry a 5-Year Prorated Warranty with the following terms:

  • Years 1-2: Products found to be defective in materials or workmanship during the first two years will be, at Mitek's option, repaired or replaced by Mitek at no charge. The warranty period does not renew, but continues on from the original date of purchase.
  • Years 3-5: The purchase price of an item which becomes defective after the first two years and prior to the end of the warranty period will be prorated and credited toward the purchase of a new MTX product. The amount of proration is determined by dividing the original purchase price by the number of months in the warranty period (60), then multiplying the result by the number of months remaining in the warranty period.

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 verify what’s in the box, 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.

Customer Q&A

1 question already asked

The Crutchfield Rewards program gives you 1 point for every dollar you spend + an additional 50 points just for creating a free Rewards account. Once you've earned 250 points or more, you can turn your points into a Rewards Gift Card that you can use toward future Crutchfield purchases. They're redeemable at a value of 2% cash back, so 250 points = $5 gift card, 500 = $10, 1,000 = $20 etc. etc. Here's a link to more info on our Rewards program: [ Larry  Nov 20, 2015 ]  Staff