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If you're into great sound, you'll love Kicker's ZX series amplifiers. These high-end amps set the standard for powerful sound, with a distinctive look that'll make your installation stand apart from the crowd.

The ZX650.4 4-channel amp will drive your speakers with 120 watts per channel. No inflated "peak power" ratings here — you can trust that this amp's CEA-2006 compliant rating reflects a true measure of its capabilities. Efficient heat sinks and rugged internal components ensure reliable operation and clean power output when the volume is cranked.

The built-in variable frequency filters adjust the amp's output to get the most out of your speaker setup, whether you're running full-range speakers or subs. Use the bass boost control to dial in the exact amount of low-end bump you're looking for.

Product Highlights:

  • 4-channel car amplifier
  • 120 watts RMS x 4 at 4 ohms (170 watts RMS x 4 at 2 ohms)
  • 325 watts RMS x 2 in bridged mode (4-ohm stable in bridged mode)
  • variable high- and low-pass filters (50-200 Hz, 12 dB per octave)
  • variable bass boost (0-18 dB at 40 Hz)
  • top-mounted controls
  • CEA-2006 compliant
  • speaker- and preamp-level inputs
  • fuse rating: 40A x 2
  • 4-gauge power and ground leads and an 80-amp fuse recommended — wiring and hardware not included with amplifier
  • 20"W x 2-1/8"H x 9-9/16"D
  • warranty: 2 years
  • 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.

Kicker ZX650.4 Reviews

Average Customer Review:

4 Reviews


Written by: ascalon from San Diego, CA on February 8, 2008

And they do it well! I bought this amp to power Polk MMC6500 components and MB Quart RVF216 coaxials/components at 4 ohms. This amp is so friggin powerful, it threatens to blow both of these speakers at times (and the gain is set well below what I would expect for the head unit)! If there is a higher threshold, I don't think my ears could withstand it. The amp performs admirably with juice to spare. Kicker makes me happy!



Night and Day

Written by: hondaclf from Baldwin, NY on January 22, 2008

Over the last year I've added two of these amps to my system, each one currently pushing a set of Polk components (rated for ~100watts RMS)from "Amp 1" and one Sub on the bridged "Amp 2". One of the other reviewers was right about the power of the amps, called the 650.4(all channels driven total RMS=650, read the tech specs), my two amps have birth sheets that say 716 and 753! The Polks sound incredible with the 120+watts RMS going through them and the subs with the 325+ RMS going through. I can only imagine what would happen if I pushed these things more. Soon moving on in the right direction with a Class D amp for my Sub(s), also upgrading those to either 1 or 2 Kicker Subs. For the price, you just can't beat the QUALITY and the POWER that Kicker has to offer.



Great sounding amp

Written by: Casey from Arkansas on June 5, 2007

This amp is Very powerful and efficient. I have it running 4 Infinity References (2-60Watts RMS) and it is barley up at all. The amp provides much more cleaner power than most other amps, and the sound differences is very noticeable. If you have high power speakers(and i mean really high power, cause this thing is way under-rated...650Watts...mine came with the certificate saying it pushed 760Watts in Kicker tests..) and you want to push them to the limit, get this amp.

The only thing that might stray you away from this amp is it's high price, but once you hear quality speakers being pushed by it, you'll never want to hear anything but.



Kicker Rocks!

Written by: Billy from Atlanta, GA. on November 26, 2006

I recently purchased the kicker zx650.1 it was a little more than what I wanted to spend but I got way more than what I paid for. I am using all four channels. Up front I am running a pair of infinity reference series 6010cs rated 2-90 watts rms, the pair in the rear is the infinity reference series 6012i rated at 2-50 rms the amp can barely even be turned up a third of the way with out fear of blowing my speakers. I highly recommend this amp, on the same note I also recommend you do your research and choose you speakers wisely. This amp puts out enough power to blow any of your most common high end aftermarket midranges. truely impressed, again.



Hands-on research

What's in the box?

Download owner's manual

  • 4-Channel amplifier with two 40-amp fuses in chassis
  • 2 Spare 40-amp fuses
  • Two 4-wire Molex harnesses for speaker-level input connection
  • 4 Self-tapping mounting screws (Length=3/4")
  • 3mm Allen wrench
  • Owner's Manual
  • Product Registration Card (return for free Kicker decal and catalog)
  • Certified Power certificate

Product Research

Inputs and Outputs

Wiring Recommendation


Terminology: Although the ZX650.4 is a 4-channel amplifier, Kicker uses the terminology of "Amp 1" and "Amp 2" to indicate the channels.

CEA 2006 Compliant: The ZX650.4's power ratings are measured according to the strict standards dictated by the Consumer Electronics Association (CEA). These standards allow you to accurately compare the rated power output of all CEA 2006-compliant amplifiers, even if they come from different brands. Manufacturers who adhere to the standards can display the CEA 2006 logo on their products and packaging.

Kicker "Living Loud" Certified Power Certificate: The amplifier comes with a certificate that indicates the total maximum wattage of the particular amplifier, along with the model number, serial number, tested date, and whether the amplifier passed the total harmonic distortion, signal-to-noise ratio, and protection circuit tests.

Speaker-level Inputs: Two high-level input connections are included to allow use with sources that do not have RCA preamp level outputs. If only one set of high level inputs is being used, you can send the signal to all four channels when the Fader button on the end of the amp is pushed out. Only one type of input signal (speaker-level or line-level) should be used with this amplifier.

Built-in Variable Electronic Crossovers: The amp features two independently-controlled crossovers that allow you to select high-pass for satellite speakers, low-pass for subwoofers, or bypass for full-range operation. The crossover frequency is variable from 50 to 200Hz.

KickEQ Bass Boost: The two KickEQ bass boost circuits provide up to 18dB signal boost at 40Hz.

Fader Button: The unit has a Fader button which gives you control of the output of the amplifier. If you are using two sets of line-level or speaker-level inputs, the Fader button should be pushed in so the receiver's fader control will operate properly. If only one set of inputs is being used, the Fader button should be pushed out so the signal can be sent to all four of the amplifier's channels.

SORT (Short circuit, Over-voltage, Reverse polarity, Thermal) Protection Circuitry: The SORT protection circuitry guards against accidents and undesired operation. The Power LED on the left side of the amp glows green and the power indicator on top of the amp glows red when the amplifier is connected correctly and SORT has not been engaged. If the red Protection LED illuminates, SORT has been engaged and the amplifier is in protect mode until the problem is resolved.

Stereo Bridged Operation: You can operate the ZX650.4 in a stereo bridged operation, with one amp driving two full-range speakers and the other amp bridged to drive a single 4-ohm subwoofer. This is also referred to as "3-channel" mode.


Top of Amplifier:

  • Amp 2 Controls:
    • KickEQ Bass Boost Control: rotary control, boosts the bass at 40Hz from 0 to +18dB
    • Gain Control: rotary input gain control
    • Variable Crossover Frequency Control: adjustable from 50-200Hz
  • Amp 1 Controls:
    • KickEQ Bass Boost Control: rotary control, boosts the bass at 40Hz from 0 to +18dB
    • Gain Control: rotary input gain control
    • Variable Crossover Frequency Control: adjustable from 50-200Hz

Right Side of Amplifier:

  • Amp 1 Crossover Mode Switch: Off, Hi, or Lo
  • Amp 2 Crossover Mode Switch: Off, Hi, or Lo
  • Fader Button: Pushed in when 2 sets of inputs used, Pushed out when only 1 set of inputs used

Inputs and Outputs

Left Side of Amplifier:

  • 12+ (power): gold-plated set screw terminal (accepts up to 4 gauge wire)
  • REM (remote turn-on): gold-plated set screw terminal (accepts up to 8 gauge wire)
  • GND (ground): gold-plated screw set terminal (accepts up to 4 gauge wire)
  • Fuse: two 40-amp fuses

Right Side of Amplifier:

  • Amp 1 Speaker Output: gold-plated set screw terminals for 2 speakers (accepts up to 8 gauge wire)
  • Amp 1 High Level Input: Molex plug input for included harness
  • Amp 2 High Level Input: Molex plug input for included harness
  • Amp 1 RCA Input: gold-plated RCA line input jacks
  • Amp 2 RCA Input: gold-plated RCA line input jacks
  • Amp 2 Speaker Output: gold-plated set screw terminal for 2 speakers (accepts up to 8 gauge wire)

Wiring Recommendation

Amplifier Wiring: This amplifier uses two 40-amp fuses, so its total fuse rating is 80 amps. If you are using an amplifier wiring kit, it should include a fuse rated at a minimum of 80 amps. Some 4-gauge amp wiring kits carried by Crutchfield include a 60-amp fuse. If you are using a kit with a fuse rated less than 80 amps, the fuse should be replaced with an 80-amp fuse.

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.