Pioneer GM-A4704 520W 4-Channel Bridgeable Amplifier

Sale price $179.00 Regular price $210.00

A Combination of Great Design and Massive Power


The GM-A4704 amplifier gives you total installation freedom and no distortion. With a one-body heat sink and gain adjustment of up to 6.5V, you can turn your in-car audio experience into the sound staging environment that you’re looking for. This 4-channel amp allows you to drive multiple speakers and subwoofers, it’s also bridgeable to power a single sub.

  Variable High Pass Filter

Variable HPF (high pass filter) allow for adjustable frequency from 40 Hz to 500 Hz* and greater car audio system flexibility according to subwoofer characteristics and personal listening preference.

  Growing Power, Shrinking Size

New Pioneer amps brilliantly integrate high-power performance superior to that of previous models in space-efficient sizes for flexibility of installation in various car cabins.

  Automatic Signal Sensing & Turn On

Pioneer amplifiers automatically select the proper input signal mode, either RCA or speaker level. When the receiver is turned on, the amplifier automatically turns on. When connected to an OEM receiver or a receiver without RCA output and utilizing speaker level output, the amp automatically senses the input mode and powers up in sync with the receiver.

When connected to an OEM receiver or a receiver without RCA output using speaker wire, the amplifier is turned on at the same time as the receiver. Pioneer’s amplifiers automatically detect the input signal and select RCA level or speaker level.



  • RCA Inputs: 4-CH
  • Amplifier Class: Class AB
  • Hi-Res Certified: No
  • Bridgeable: Yes
  • Warranty: 1 Year
  • Speaker Level Input: Yes
  • Fuse Rating: 30A x 1
  • Bass Boost Remote: No
  • Automatic Signal Sensing and Turn-On: Yes
  • Hi-Volt Input Level Control: 0.3V to 6.5V (RCA in), 3.0V to 26V (SP in)
  • Terminal Type: Screw
  • Load Impedance Allowance (Ohms): 2 to 4
  • Protection Control System: Yes
  • Dimensions: 326(W) X 60(H) X 215(D) mm


  • Continuous Power (RMS) Output @ 1Ω: N/A
  • Continuous Power (RMS) Output @ 2Ω: 65W x 4
  • Continuous Power (RMS) Output @ 4Ω: 40W x 4
  • Continuous Power (RMS) Output - Bridged @ 4Ω: 130W x 2

Audio Adjustments

  • Low-Pass Crossover Frequency: 80 Hz
  • Low-Pass Slope (dB/octave): -12db/oct (A/B CH)
  • High-Pass Crossover Frequency: 40 Hz to 500 Hz
  • Bass Boost Frequency: 50Hz
  • Bass Boost Level: 0/6/12dB

Audio Specifications

  • Frequency Response: 10Hz ~ 70kHz (+0dB , -3dB)
  • Total Harmonic Distortion (THD): <0.05% ( 10W, 1kHz)
  • Signal-to-Noise (SN) Ratio: > 94dB