Skip Navigation

MTX Road Thunder RT604

4-channel car amplifier — 60 watts RMS x 4

1 Review

Item # 236RT604

This item is no longer available.

Shop all Car Amplifiers


Our take on the MTX Road Thunder RT604

An MTX Road Thunder amp puts your music up front and in your face — in a great way. You won't stop smiling when you finally hear all the musical details and and feel the awesome bass that your old system just couldn't reproduce.

An MTX Road Thunder amp puts your music up front and in your face — in a great way. You won't stop smiling when you finally hear all the musical details and and feel the awesome bass that your old system just couldn't reproduce.

4-channel workhorse
The RT604 4-channel amp will get your whole car rockin' with 60 watts RMS to each of your front and rear speakers. Or, if you choose, you can switch the amp over to 2-channel mode to drive a pair of subs with 180 watts RMS each. You'll find the built-in high- and low-pass filters useful in matching the amp to your particular speakers or subs.

Reliable performance
When the beat gets hot during heavy play, this amp's inner works stay cool by shedding heat efficiently through a tough, extruded aluminum top cover and heatsink assembly. This Road Thunder amp features speaker-level inputs, which come in handy if you're hooking it up to a factory radio.

Great amp, gets warm though

MTX Road Thunder RT604, Queens, NY

What's in the Box:

  • 4-Channel amplifier
  • Four 30A ATO fuses (two installed)
  • Two 11" Speaker level input harnesses
  • Four 3/4" Self-tapping screws
  • 4 Flat washers
  • 3mm Allen wrench
  • 2.5mm Allen wrench
  • Instruction manual (English/ French/ Spanish/ German/ Italian/ Portuguese/ Dutch/ Russian/ Finnish/ Polish)

Product Highlights:

  • 4-channel car amplifier
  • 60 watts RMS x 4 at 4 ohms (90 watts RMS x 4 at 2 ohms)
  • 180 watts RMS x 2 bridged (4-ohm stable in bridged mode)
  • CEA-2006 compliant
  • frequency response: 20-30K Hz
  • Class AB amp technology
  • variable high- and low-pass filters (40-400 Hz, 12 dB/octave)
  • preamp and speaker-level inputs
  • fuse rating: 30A x 2
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 14-3/8"W x 2-1/8"H x 7-1/8"D
  • warranty: 5 years (free repair or replacement for 2 years; prorated replacement for years 3 through 5)
  • Our 60-day money-back guarantee

MTX Road Thunder RT604 Reviews

Average Customer Review(s):

(1 Review)
rewards card

Submit a review and enter to win a $350 rewards card

Review this product

Thanks for submitting your review

Most reviews are processed and published within 5 business days. You will receive a confirmation email once your review has been published.

Your Review

Use the stars below to rate the overall product on a scale of 1-5
Upload your photos

Not visible. Email associated with order.
(e.g., Charlottesville, VA)

Additional Fields (optional)


By submitting this review, you agree to our terms and review guidelines.

Filter by rating

Customer photos

<< >>

Hands-on research

Product Research



CEA-2006 Compliant: CEA-2006 is a system of testing and measurement methods for mobile audio amplifiers. This voluntary standard advocates a uniform method for determining an amplifier's RMS power output and signal-to-noise ratio. The criteria for measuring power uses a DC input voltage of 14.4 volts and the RMS power output is measured into a 4-ohm load, with 1% or less Total Harmonic Distortion plus noise (THD+N), and at a frequency range of 20 Hz to 20,000 Hz when applicable. Signal-to-Noise ratio is measured in weighted absolute decibels (dBA) at a reference of 1 watt into 4-ohms. CEA-2006 allows consumers to compare car amplifiers and receivers on an equal basis. The MTX Road Thunder RT604 under CEA-2006 regulations is rated at 60 watts RMS x 4 channels with an 80 dBA signal to noise ratio.

2-Ohm Stable: The RT604 is capable of handling load impedances down to 2-ohms in stereo; the amplifier is rated at 90 watts RMS x 4 channels into 2-ohms with no more than 1% THD+N.

Bridgeable: The front and rear sections of the amp are independently bridgeable; the bridged output is 180 watts x 2 channels at 4-ohms (or 180 watts x 1 and 60 watts x 2 if only one half of the amp is bridged).

Protection Circuits: The RT604 provides Thermal and Short-circuit protection.


Gain: The front and rear sections of the amp have independent gain controls. Each rotary knob is continuously variable from 100 mV to 6 V.

Crossovers: The crossovers are also independent for the front and rear amplifiers:

  • Mode: front and rear 3 position switches; High Pass, Low Pass, Full Range
  • High Pass: front and rear rotary controls; 40 Hz to 400 Hz
  • Low Pass: front and rear rotary controls; 40 Hz to 400 Hz


Power/Ground/Turn-On Connections: The RT604 features set-screw terminals for the Power, Ground and Remote turn-on leads. The Power and Ground terminals will accommodate up to 4 gauge wire, the Remote turn-on terminal will accept up to 8 gauge wire.

Speaker Connections: The amplifier is equipped with four set-screw speaker terminals. The terminals will accommodate up to 8 gauge speaker wire.

Line Level Inputs: MTX recommends using the front and rear RCA type line-level inputs if possible.

Speaker Level Input: Use the included front and rear speaker level input harnesses if the connected radio has no preamp outputs.

Fuse: The amplifier is equipped with two ATO type 30 amp fuses; they're located under a cap on the bottom panel.


5 Year Warranty Terms: This product carries 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.