What the four channels can drive
The GM-A4704 gives you four channels at 40 watts RMS each into 4 ohms, or you can bridge two channels into 130 watts RMS per pair. That shape suits a system with separate front and rear speakers, or a front stage plus a bridged subwoofer stage.
Speaker-level and line inputs both appear on this amplifier, so the install question is whether your head unit offers the matching output type. We'd consider it a sensible first upgrade for a stock system that needs more clean output before you start swapping speakers.
| Product detail | Value to match to your vehicle |
|---|---|
| Product | Pioneer GM-A4704 520W Max Class AB Bridgeable |
| Model | GM-A4704 |
| Color | Black/red |
| Size | 4-Channel - 520W |
A diagnostic boundary to remember
A discount on an amplifier is not evidence that your current audio fault is amplifier-related. This amp is a supported upgrade for adding clean power, front-to-rear balance and subwoofer output, not a diagnostic fix for a dead channel or a wiring fault.
The variable high- and low-pass filters let you tune which frequencies reach your speakers, which is a real functional difference if you want to shape tone without adding a separate processor. If your issue is no sound at all, get the signal path checked first.
The GM-A4704 adds power and tone shaping; it does not diagnose an existing fault
High- and low-pass filters are variable, so you can set the range per install
What the current offer is worth
- Amazon price
- $110.50
- Customer rating
- 4.5
- Customer reviews
- 283
- Typical price over 90 days
- $125.69
- Difference
- $15.19 (12 percent)
At $110.50, this amp is $15.19 under the typical price over the last 90 days of $125.69. That current listing runs 12 percent below the recent typical, so the savings are a snapshot of a moving market rather than a fixed markdown.
The power and wiring check
Before buying, confirm your vehicle's charging output and the amplifier wiring you intend to run. This amp needs a fused power feed from the battery and a solid ground, and you should verify the wire gauge against the fuse rating you plan to use.
Also decide where it will live. The GM-A4704 needs a mounting spot with airflow, because Class AB designs generate more heat than small digital amps. A location under a seat or behind a panel is fine if it stays clear of moving parts and stays reasonably ventilated.
Who should choose this amp
Choose the GM-A4704 if you want a four-channel Class AB amp for a basic speaker plus subwoofer system and you are comfortable confirming the install details yourself. Skip it if your head unit lacks a compatible output, if you need digital signal processing, or if you want a smaller high-efficiency chassis.
Before you order, verify the output type on your radio and the power and ground path you will use.
Specifications
| Model | GM-A4704 |
|---|---|
| Color | Black/red |
| Size | 4-Channel - 520W |