Why Choose Crutchfield?
Great gear and expert advice
Our experts help you pick the ideal gear for your needs.Meet our advisors
Free tech support for the life of your gear.Read about our one-on-one expert help
You may return items that are complete and like new for any reason within 60 days.See the details of our return policy
Earn one point for every dollar you spend and use those points to save on future purchases.Get full details on Crutchfield Rewards
Deep discounts on car installation gear
We offer vehicle-specific installation instructions, dash kits, wiring harnesses, and speaker accessories at deeply discounted prices with car stereo and speaker purchases. Available for most vehicles.Learn more
Trusted since 1974
Our customers have trusted us with their business, and they’ve helped us win awards for our service.Check out our most recent awards
The manufacturer’s warranty always applies.See more details
4-channel car amplifier 75 watts RMS x 4
Our take on the MTX THUNDER75.4 by Crutchfield's Buck Pomerantz
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
Great power and very low distortion at high volumes! I paired this amp with 2 (front & rear) sets of Infinity Reference REF-6520cx 6-3/4" Component System (Item #108R6520CX). I've honestly never turned the volume past %30 and the amp still has plenty of room to boom! Absolutely a great amp.
Ryan, Prairie Village, KS
What's in the Box:
- 4-Channel amplifier
- 4mm Allen wrench
- 2mm Allen wrench
- Four 1/2" Self-tapping screws
- Owner's manual (English/ Spanish/ Portuguese/ French)
- 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: 2 years
- Our 60-day money-back guarantee
MTX THUNDER75.4 Reviews
Average Customer Review(s):
Thanks for submitting your review
Features and Specs
|RMS Power Output (Watts x Channels)||
75 x 4
|Peak Power Output (Watts x Channels)||200 x 4|
|Power at 2 Ohms (Watts x Channels)||100 x 4|
|Bridged Power (Watts x Channels)||200 x 2|
|Minimum Impedance Bridged||4|
|Minimum Impedance Unbridged||2|
|Best Frequency Response||15-25000 Hz|
|THD at Rated RMS Power||0.05%|
|Signal to Noise Ratio||78 dB|
|Low-Pass Crossover Frequency||50-750 Hz|
|Low-Pass Slope (dB/octave)||12 dB/octave|
|High-Pass Crossover Frequency||10-750 Hz|
|High-Pass Slope (dB/octave)||12 dB/octave|
|Bass Boost Frequency||N/A|
|Speaker Level Inputs||No|
|Parts Warranty||2 Years|
|Labor Warranty||2 Years|
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.
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.
Why did you buy this?
In my youth ran across a MTX 225ho, OMG...That amp was a beast. Been a fan ever since. [ Michael Feb 24, 2017 ]
Perfect for my Rockford Fosgate 6x8's [ Patrick Dec 01, 2016 ]
Upgrading from a 60Wx4. This is a perfect fit for new speakers in the front and the ones I currently have in the back. [ Daniel Nov 29, 2016 ]
Great rating. Seemed like a nice addition to my system. [ Paul Nov 22, 2016 ]
ziggy's recommendation [ Laurie Oct 05, 2016 ]
I need to power my 6x9s in the rear deck and the 4x6s in the door, this amp will supply enough RMS power and has a low THD%. [ Claude Aug 29, 2016 ]
SPACE CONCERNS [ JAMES Jul 27, 2016 ]
Highly rated, fits for my system. [ Joseph May 20, 2016 ]
Fits my speaker very well, and seems like a great quality. [ Kane Feb 23, 2016 ]
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: http://www.crutchfield.com/Support/rewards.aspx? [ Larry Nov 20, 2015 ] Staff