Better sound in your car

This Kicker ZX650.4 4-channel amplifier will power up your music with 120 watts RMS to each of your four speakers or components, perfect for handling your front and rear speakers.As another option, you can put the amp in 2-channel mode to drive a couple of subwoofers with up to 325 watts RMS each. This amp will run reliably even when pushed hard, due to its heavy-duty internal components and the efficient cooling system it employs as it boosts your music's power.

Works with almost any stereo

Kicker employs their Fail-Safe Integration Technology (FIT™) to reject noise and stop any interference generated by your car's electronics, so you'll enjoy your music clean and pure. Speaker-level inputs make it simpler to hook this amp up to a factory system. You can tune for almost any speaker or subwoofer system with the variable high- and low-pass filters, while an adjustable bass boost gives you even more kick when needed. When you use the amp's rear channels to power a sub, an optional wired remote bass level controller lets you adjust the bass level from the front seat.

Product Highlights:

  • 4-channel car amplifier
  • 120 watts RMS x 4 at 4 ohms (160 watts RMS x 4 at 2 ohms)
  • 325 watts RMS x 2 bridged at 4 ohms (4-ohm stable in bridged mode)
  • CEA-2006 compliant
  • variable high- and low-pass filters (50-200 Hz, 12 dB/octave)
  • variable bass boost (0-18 dB at 40 Hz)
  • Class AB amp technology
  • Fail-Safe Integration Technology eliminates noise from your vehicle's electrical system
  • preamp and speaker-level inputs (speaker-level input requires an optional adapter)
  • optional wired ZXRC Remote Bass Control available for rear channels
  • 4-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • fuse rating: 40A x 2
  • 20"W x 2-1/8"H x 9-5/8"D
  • warranty: 2 years (extends to 3 years when purchased with either a Kicker single amp wiring kit or a Kicker multi-amp kit)
  • 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.

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Hands-on research

What's in the box?

Download owner's manual

  • 4-Channel amplifier
  • Two 40-amp fuses (installed)
  • Owner's manual (English/ Spanish/ German/ French)

Product Research



4-Channel Amp: The front and rear sections of the amplifier (labeled Amp1 and Amp2) have independent gain, crossover, and bass boost controls.

Gain: The rotary gain controls are continuously variable from 125 mV to 5 V when the Input Sensitivity switch is set to Low and 250 mV to 10 V when the Input Sensitivity switch is set to High.

Crossovers: The front and rear crossovers can be independently set to high-pass, low-pass, or turned off (full range). The crossover points are continuously variable from 50 to 200 Hz and the slope is 12dB per octave.

Auto Turn-on Switch: The amp offers three automatic turn-on modes; select from:

  • +12V: connect a wire from the remote turn-on lead from your source unit to the REM terminal on the amplifier; this is the preferred turn-on method
  • DC Offset: turns the amp on when a 6-volt DC offset is detected at the high-level speaker inputs when the source unit is turned on
  • Audio: detects the incoming audio signal from your source unit and automatically turns the amp on; will not work if the input gain control is not set properly

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

Fader: When powering four speakers and using both the front and rear inputs, turn the fader switch on. To supply all four channels from only one input, turn the fader switch off.

ZXRC Remote Bass Control: When the Amp2 section crossover is set to low-pass, an optional wired remote bass control (item number 20610ZXRC, sold separately) can be used to remotely adjust the bass level output.


Left Side of Amplifier:

  • +12V (power): set screw terminal
  • REM (remote turn-on): set screw terminal
  • GND (ground): set screw terminal
  • Fuse: two 20-amp ATO fuses

Right Side of Amplifier:

  • Speaker Outputs: four pair of set screw terminals
  • RCA Input: two pair of stereo RCA input jacks; also used for speaker level input (item number 206KiSL needed, sold separately)

Amp Wiring Kit: Kicker recommends using a 4-gauge wiring kit with this amplifier.

Our Product Research Team

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