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The Clarion APX2120 2-channel amplifier pumps out 60 watts RMS per channel, with the versatility to work in a variety of systems. This stereo amp delivers full-frequency response from 20 to 30,000 Hz, so you can use it to power a set of full-range speakers, or to drive a subwoofer system.

You can tune the APX2120 for use in your system with its built-in variable high- and low-pass filter and selectable bass boost. Speaker-level and preamp-level inputs allow you to hook into almost any factory or aftermarket stereo. However you use it, this amp will supply your system with accurate, reliable power.

Product Highlights:

  • 2-channel car amplifier
  • 60 watts RMS x 2 at 4 ohms (90 watts RMS x 2 at 2 ohms)
  • 100 watts RMS x 1 bridged output at 4 ohms (4-ohm stable in bridged mode)
  • variable high- and low-pass filter (50-300 Hz, 12 dB/octave)
  • selectable bass boost (0, 6, 12 dB at 50 Hz)
  • Class-AB amplifier design
  • MOSFET power supply
  • CEA-2006 compliant
  • speaker- and preamp-level inputs
  • gold-plated connector terminals
  • fuse rating: 25A x 1
  • 8-gauge amp wiring kit recommended — wiring and hardware not included with amplifier
  • 10-5/8"W x 2-3/4"H x 10-7/8"D
  • warranty: 1 year
  • 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.

Clarion APX2120 Reviews

Hands-on research

What's in the box?

Download owner's manual

  • Two-channel amplifier
  • 12" High-level speaker input harness
  • 4 Self-tapping screws (length=1")
  • 4 Rubber washers
  • Owner's Manual

Product Research



Crossover: The Clarion APX2120 amplifier includes a continuously variable 50-300 Hz crossover to filter out the highs from your subwoofer, or the lows from your full-range speakers. The crossover has a 12dB/octave slope. You can set the crossover to LPF (low-pass filter) or to HPF (high-pass filter). For full range operation, you can set the X-Over mode to "Off" and the Frequency control has no effect.

Bass Boost: You can engage a narrow frequency band (High Q) bass boost circuit to compensate for a less than ideal subwoofer enclosure design. The added boost produces rich, full bass tones that are normally difficult to reproduce in a car audio environment. The Bass Boost circuit has a fixed frequency at 45Hz. You can select a gain of +6db or +12dB, or select "Off" if you don't want to boost the bass frequencies.

Protection Circuitry: The amplifier has a two-way protection circuitry. The amplifier will shut down when the operating temperature is too high and when the speaker outputs are shorted. A red LED on the left side of the amplifier glows when the amp has shut down and is in protection mode.

Speaker-level and Line-level Inputs: The amp provides both line-level and speaker-level inputs. If connecting a receiver with line outputs, you can use an RCA stereo patch cable. If the receiver does not have line outputs, you can splice the supplied high-level speaker input harness to the receiver's left and right speaker wires, then plug the harness into the amplifier.

Gold-plated Terminals: The APX2120 features gold-plated connections, including the screw terminals for power, ground, remote, and speakers, as well as the RCA line inputs. These gold-plated terminals prevent corrosion and provide excellent signal transfer.

CEA-2006 Compliant: CEA-2006 is a system of testing & 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 (THD) plus noise. CEA-2006 allows consumers to compare car amplifiers and receivers on an equal basis.


Left Side:

  • Gain Control: a rotary control used to set the amplifier's input sensitivity to match the level of the incoming signal
  • Bass Boost control: a 3-way switch used to set the bass boost from 0 (center position) to +6dB (left) or +12dB (right) at 45 Hz
  • Crossover (X-OVER) Control:
    • Frequency: a rotary control that sets the crossover cut off frequency from 50 to 300Hz
    • Mode: a 3-way switch used to set the crossover to Low Pass Filter (LPF), High Pass Filter (HPF) or Off (Full Range)


Left Side:

  • Low Input: 1 pair of stereo RCA inputs
  • High Input: 5-pin plug-in clip for use with the supplied high-level speaker input harness

Right Side:

  • Speaker Terminals: 2 pairs of gold-plated screw terminals. A label indicates left + and -, right + and -, and bridged + and - terminals.
  • +12V (power): screw terminal (accepts up to 8-gauge wire)
  • GND (ground): screw terminal (accepts up to 8-gauge wire)
  • REM (remote turn-on): screw terminal (accepts up to 8-gauge wire)
  • Fuse: 25-amp fuse (inserted)



  • RMS power at 4 ohms: 60 watts x 2 (10Hz-20kHz, at 0.1% THD)
  • RMS power at 2 ohms: 90 watts x 2 (10Hz-20kHz, at 0.1% THD)
  • RMS power bridged mode into 4 ohms: 100 watts x 1 (10Hz-20kHz, at 0.1% THD)
  • Max power output at 4 ohms: 200 watts
  • Signal-to-Noise Ratio: ≥85 dB
  • Frequency Response: 20Hz-30kHz Full Range
  • Input Impedance: 22k Ohm
  • Allowable Battery Voltage: 9.6-15.6V

Our Product Research Team

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