Expert Service 1-877-289-7664 [Hours]

MTX Audio XThunder 704X

420W RMS, 4-Channel Amplifier X Thunder 704 X

Discontinued
|

We apologize

This item has been discontinued

  • X Thunder Series 4-Channel Class AB Car Amplifier
  • RMS Power Rating:
    • 4 ohms: 70 watts x 4 chan.
    • 2 ohms: 105 watts x 4 chan.
    • Bridged, 4 ohms: 210 watts x 2 chan.
  • Max power output: 840 watts
  • Patented Adaptive Class AB Technology
  • LED power indicator
  • Anodized Finish
  • Single channel operation
  • Chrome X Thunder Badge
  • Stereo gain control
  • Heavy duty aluminum construction with large heat-sinks
  • Variable high-pass filter (40-8000 Hz, 12 dB/octave)
  • Variable low-pass filter (40-800 Hz, 24 dB/octave)
  • Frequency response: 20-20000 Hz
  • Dimensions: 15" L x 9-1/8" W x 2-1/4" H
  • 4-gauge power and ground leads recommended. Contact us for information regarding a discount on a select amplifier kit when purchased together.
  • Authorized Internet Dealer
  • 1-year Manufacturer's warranty

Power Specifications - Full Range Channels

RMS Power @ 4 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 4 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

70 watts x 4 channels
RMS Power @ 2 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 2 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

105 watts x 4 channels
Bridged RMS Power

Bridging refers to combining two channels on an amplifier to create one channel with double the voltage and an increased power output. A 2-channel amplifier will bridge down to 1-channel and a 4-channel amplifier can bridge to create 2-channels. An amplifier is most commonly bridged to drive a subwoofer.

Remember, once you bridge two channels down to one its final impedance will be 4 ohms unless otherwise specified. This rating lists the RMS power created once an amplifier is bridged.

210 watts x 2 channels

Amplifier Specifications

Amplifier Class

An amplifier increases the power of the signal being fed to it by taking energy from its power supply and matching the signal but increasing its amplitude. Amplifiers use many different methods for converting these electrical signals and have been categorized into classes.

Class A/B: Greater than 50% of the input signal is amplified while the other percentage is “off”. These amplifiers have a small amount of current flowing through the output transistors all the time which almost eliminates crossover distortion. Class A/B has great sound quality but is not as efficient as class D. These amps are most commonly used to drive speakers.

Class D: Also known as switching amplifiers, class D amps have output transistors that are completely turned “on” or “off”. This means that when the transistors are on, there is almost no voltage across them but when they are off there is significant voltage but no current flowing through it which makes these amplifiers very efficient at the cost of sound quality. These amps are most commonly used to drive subwoofers.

Other Classes: You may see classes such as GH, bD, X, FD, etc. by some manufactures. These amplifiers tend to be either class A/B, D or a hybrid of the two but with improvements to their designs that can make them more efficient or offer better sound quality.

AB
Number of Channels
Each channel on an amplifier will power one speaker using a positive and negative cable. There are various types of amplifiers, each designed to power a certain number of speakers. Monoblock amplifiers, also known as single channel, are designed to power one or more subwoofers. These amplifiers often have very high power ratings. On the other hand, multi-channel amplifiers power multiple speakers, usually at lower power ratings. 2-Channel and 4-Channel amplifiers can power car speakers or low powered subwoofers. Occasionally you might see a 5 or 6-channel amplifier that can power speakers and subwoofers at the same time. The most common setup is a monoblock amp to run subwoofers and a 4-channel amp to run door speakers. Check out our Knowledge Base for more information.
4
Total Peak Power Output
The total peak power output is measured as the wattage per channel multiplied by the number of channels, and is calculated at the lowest level of operating impedance.

It is measured during a brief musical burst, such as a sudden drum accent. Some manufacturers display peak power ratings on the face of their products to increase the appeal.

The RMS power rating is more accurate, and we recommend using it for product comparison.

840 watts
Total RMS Power Output
Total RMS power is measured by multiplying RMS power per channel by the number of channels, and is calculated at the lowest level of operating impedance.

RMS power is the amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds.

The RMS output figure is much more accurate than the peak rating when comparing products.

420 watts
Maximum Input Gauge Size
This is the largest gauge wire that will fit into the power and ground terminals of this device. The lower the gauge number, the thicker the wire is. For example, a 4 gauge wire is thicker than an 8 gauge wire and thus has higher current carrying capacity. Always do your best to get this size wire to reduce the risk of damage to your components.
4 AWG
Minimum Impedance Unbridged
The lowest impedance the amplifier will handle when it is not bridged.
2 ohms
Minimum Impedance Bridged
The lowest impedance the amplifier will handle when it is bridged.
4 ohms
THD at Rated RMS Power
The amount of change in harmonic content of the signal as it is amplified. A lower figure indicates less change and a more accurate amp. THD below 0.10% is inaudible.
1%
Speaker Level Inputs
Speaker level inputs are commonly referred to as high-level inputs and vice versa. This input type allows you to get your audio signal directly from the speaker wire in your vehicle, instead of using RCA cables. The advantage of this is factory integration, as most stock radios do not have RCA outputs to run amplifiers.
Yes
Preamp Outputs
Many amplifiers are equipped with RCA preamp outputs which pass the original music signal from the source to additional amplifiers. This is known as daisy chaining because the source connects to the first amp, and the first amp connects to the second amp, etc. The advantage to daisy chaining is you only need one 2-channel RCA cable to transfer the signal from the head-unit to the amplifier, and then one additional cable for each amp being daisy chained.
No
Built-in Crossover

A crossover is a type of filtering system that permits only certain frequencies to play. A Low-Pass (LP) crossover allows only frequencies below its setting to get through which is good in the case of some subwoofers. A High-Pass(HP) filter allows frequencies above its setting to pass through, this is normally used on speakers.

When a crossover is set to FULL it means no filtering is added and the full frequency spectrum is allowed through the amplifier. Filtering is important because feeding a speaker frequencies it cannot reproduce effectively creates distortion.

Low-pass (LP)
High-pass (HP)
High-Pass Crossover Frequency
The high-pass crossover frequency can be a fixed crossover point or a variable crossover range. A variable high-pass crossover allows you to select a specific crossover point which allows frequencies above the set crossover point to pass, while making frequencies below the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

40 - 8000 Hz
Low-Pass Crossover Frequency
The low-pass crossover frequency is typically used for subwoofers. It can be a fixed crossover point or a variable crossover range. A variable low-pass crossover allows you to select a specific crossover point which allows frequencies below the set crossover point to pass, while making frequencies above the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

40 - 800 Hz
Signal-to-Noise Ratio
This spec compares the strength of the signal to the level of background noise. A higher value indicates less background noise.
75 dB
Bass/Gain Remote
If the amp comes with a bass/gain remote you will be able to control the level of your bass from your dashboard. Typically bass remotes also include a 16-20 ft. wire for installation.
No
Fan Cooled
A great feature to have if an amp generates a large amount of heat. Cooling fans can help regulate the temperature to prevent the amp from overheating (burning).
No
CEA-2006 Compliant
Amplifiers that have been tested to meet specific standards. When a car amplifier meets these standards, you can be sure that it will be able to produce the amount of power specified by the official CEA-2006 rating. Usually, these rating consist of the following items:
  • RMS Power
  • Signal-to-Noise Ratio

This rating applies to both external car amplifiers, as well as the amplifiers inside of in-dash stereos.

No

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Manufacturer

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
83%
4 Star
0%
3 Star
0%
2 Star
17%
1 Star
0%

Average Attribution Rating

Durability
4.2
Value
4.3
Features
4.2
Design
4.5
Usability
4.8

Kevin

Medford, Ny

Overall
Durability
Value
Features
Design
Usability

Meh

July 24, 2012

Had this amp for the past year and I didn't really have the right setup to test it's capabilities until I had gotten Rainbow Speakers this past spring, for a month or 2 everything sounded great 9/10 but idk if the speakers are too demanding, or if this thing is a bad in the heat as it is summer now but I suspect that this amp may be mediocre if you're looking for pure SQ, trading up and gonna probably pawn this thing to a friend.

0 of 0 found this helpful

Help our customers find the most helpful reviews

M. Conner

Fort Wayne, IN

Overall
Durability
Value
Features
Design
Usability

Great Sound Quality

April 10, 2011

As far as sound goes this amp was built very well. I was originally looking for one that had a built-in fan because I mounted the amp in the trunk of my car, however I was able to get this amp for a really good price. The sound quality really impressed me. I have it running a pair of Boston Acoustics SX50 components and a pair of BA SL60 components. Just make sure that when you mount it you give it plenty of room to breath, if you mount it in an area without much air space (like I did originally) you'll most likely have some overheating issues. But once I moved so that the front of the amp was completely open to space, I haven't had a single problem with it. I would definitely recommend this amp.

0 of 0 found this helpful

Help our customers find the most helpful reviews

chris

Saint Louis, MO

Overall
Durability
Value
Features
Design
Usability

704x

April 3, 2011

this is a great amp... sounds amazing on my components

0 of 0 found this helpful

Help our customers find the most helpful reviews

Hank

Roswell, GA

Overall
Durability
Value
Features
Design
Usability

MTX Audio XThunder 704X

May 11, 2010

This is a solidly built amplifier. I have it pushing a pair of polk db 5.25's and 6x9's and they absolutely sing. I installed it all myself which was tough to do but i saved myself a good 100 bucks. The high pass filters come in handy when running the speakers because i'm able to make sure they don't blow or get pushed to hard. I ran it with a 4 gauge wire but im sure it would be okay to do it with 8 gauge.

0 of 0 found this helpful

Help our customers find the most helpful reviews

jack

reno, nv

Overall
Durability
Value
Features
Design
Usability

MTX amp is awesome.

March 2, 2010

i have this guy powering two kicker ks components and two kicker ks coaxial 6.5"s it does an amazing job, my speakers sound super clear and loud. i definitely recommend. my only complaint is that my sub amp turns on about a second before this one, its really no big deal but thought i'd mention it. get it from sonic at the best price ever!

0 of 0 found this helpful

Help our customers find the most helpful reviews

Kadow

Pewaukee, Wisconsin

Overall
Durability
Value
Features
Design
Usability

great amp for the price

June 2, 2009

i hav this amp hooked up to a pair of MTX 6x9's and a pair of MTX 5.25's..My system sounds great. The amp puts out pleanty of power with very little or almost no distortion. Highly recomended.

0 of 0 found this helpful

Help our customers find the most helpful reviews

Accessory Tools and Products

Accessories added

NVX XKIT44 4-Gauge 4-Channel Wiring Kit

4-Channel 100% OFC Complete True 4 Gauge Amp Kit with RCA Cables and Speaker Wire

Your Price $99.99

StreetWires ZN3K-04 4-Gauge Wiring Kit

Get a matching StreetWires amp kit with your new MTX amplifier! Don't forget the RCA's!

Your Price $59.99

NVX XBG3PK 1/0 Gauge OFC Big 3 Upgrade Kit

Comes with everything you need to upgrade your power and ground wire.

Your Price $79.99

Kicker Big 3 Package 1/0 Gauge Big 3 Upgrade Kit

Get all you need including wire cutters to upgrade your power and ground wire.

Your Price $149.99

Belva BBG3KT CCA 1/0 Gauge Big Three Kit

Features everything needed to upgrade factory power and ground wire.

Your Price $39.99

Universal Remote Level Bass Control

Controls bass level and frequency via RCA/Interconnect connectors on any amp.

Your Price $7.99

Small Universal Remote Level Bass Control

The Scosche RLC is a smaller universal bass remote that connects via RCA inputs.

Your Price $11.99

StreetWires FB4

4 AWG / 4 Gauge Firewall Bushing

Your Price $6.95

NVX XDBU4 - Top of the Line!

Distribution Block with Two 1/0 or 4 AWG Inputs and Four 4 or 8 AWG Outputs

Your Price $17.99

Professional Installation for your Car Power Amplifier

Covers labor charges through our professional installer network.

Your Price $89.99

NVX XIV45 4-Channel RCA Audio Interconnect Cable

5 Meters (16.4 ft.) 4-Channel RCA Audio Interconnect Cable with Dual Twisted Pair Hyper-Flex Technology

Your Price $23.99

StreetWires ZN9 Series Interconnect Cable

16.4 ft. of 4-Channel RCA Cable with Rhodium-plated contacts and ZeroNoise construction for clear signal transfer!

Your Price $99.95

NVX XWS1225 12 AWG Speaker Wire

25 ft. of True 12 Gauge 100% Copper EnvyFlex Speaker Cable/Wire

Your Price $39.99

NVX XWS1625 16 AWG Speaker Wire

25 ft. of True 16 Gauge 100% Copper EnvyFlex Speaker Cable/Wire

Your Price $13.99

Belva BBSW127 12 AWG Speaker Wire

12 Gauge 7 Meter (23 Ft) Speaker Wire (CCA)

Your Price $14.99

Belva BBSW167 16 AWG Speaker Wire

16 Gauge 7 Meter (23 Ft) Speaker Wire (CCA)

Your Price $12.99

The Install Bay IB-CAP1F

True 1.0 Farad Car Audio Capacitor for up to 1000W Max

Your Price $37.99

e2 ECAP1 by Scosche - Mid-Level 1 Farad

Digital 1.0 Farad Car Audio Capacitor for up to 1000W Max

Your Price $49.99

Rockford Fosgate RFC1D - Top of the Line 1 Farad

Digital 1.0 Farad Car Audio Capacitor for up to 1000W Max

Your Price $104.99

SMD DD-1 Distortion Detector

Set the gain of an audio amplifier quickly and accurately

Your Price $149.99

Scosche SPL Meter SPL1000F

Handheld boomSTICK measures your SPL range from 60 to 135 dB

Your Price $21.99

AutoSound 2000 CD-102

High Frequency Test CD specifically designed for the set-up and evaluation of sound system imaging and placement.

Your Price $11.99

AutoSound 2000 CD-104

Audiophile reference series test disc for evaluation of all audio components.

Your Price $11.99

Product Summary

Manufacturer

Model Number

704X

UPC

715442241149

Weight

11.00lbs

Internal SKU

704x

Internal Product ID

9036

Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: MTX Audio XThunder 704X