Pioneer GM-A6704 4-Channel Car Amplifier – 1000W Max, Class AB, Bridgeable Design, Bridgeable, High-/Low-Pass Filters
PIONEER
Best for
Best 4-channel (full system)
Amazon rating
Amazon aggregate, one input among many in the Verdict Score
Based on 1 trusted source
Current price
$140.00
Updated May 17, 2026 · 1 min read
Sources behind this verdict
8 reviewers weighted by source trust
The consensus
What reviewers found
Synthesized across the trust-weighted source mix below.
Across the reviewers we read, the Pioneer GM-A6704 is the conservative, low-risk pick for a four-channel upgrade powering door speakers. Crutchfield's product-page review calls it a strong, affordable amp with useful built-in high-pass and low-pass filters, and r/CarAV regulars repeatedly describe Pioneer's GM line as 'decent, solid little amps' that they reach for when a customer wants quality without paying for a boutique brand. It is a Class A/B design rated at 60W RMS x 4 at 4 ohms (or 100W x 4 bridged to two channels for fronts plus a small sub), which puts it in the mid-power range for a four-channel.
What reviewers liked
- Crutchfield praises the affordability, flexibility, and built-in high/low-pass crossovers
- r/CarAV consensus describes Pioneer GM amps as solid, low-drama daily-driver choices
- Bridgeable design allows two-channel front plus sub, or four full-range channels
- Large retailer-customer base (942 reviews at 4.4) corroborates real-world reliability
Where it falls short
- Class A/B runs hotter and less efficiently than modern Class D 4-channel rivals
- Mid-tier 60W RMS x 4 leaves little headroom for power-hungry component sets
- Reviewers do not single it out for sound-quality finesse, just for doing the basics reliably
Across the reviewers we read, the Pioneer GM-A6704 is the conservative, low-risk pick for a four-channel upgrade powering door speakers. Crutchfield's product-page review calls it a strong, affordable amp with useful built-in high-pass and low-pass filters, and r/CarAV regulars repeatedly describe Pioneer's GM line as 'decent, solid little amps' that they reach for when a customer wants quality without paying for a boutique brand.
It is a Class A/B design rated at 60W RMS x 4 at 4 ohms (or 100W x 4 bridged to two channels for fronts plus a small sub), which puts it in the mid-power range for a four-channel. Walmart Business verified-purchase reviews echo the Reddit consensus: enough headroom to push four 6.5-inch coaxials cleanly, with crossover options that suit either a front-stage build or a front-plus-bridged-sub setup. Reviewers do not single it out as a sound-quality standout; the verdict is that it does the basics well and reliably.
The honest caveats are that Class A/B runs warmer and less efficient than modern Class D rivals like the Taramps TS 1200x4, and that anyone trying to drive aggressive 100W-plus component sets will quickly want more headroom. Within the daily-driver remit, the trust-weighted consensus is firmly positive.
- 4-Channel Class A/B Amp - Upgrade your car audio with a 4-channel amp for clearer sound. Customize your sound by connecting various speakers, balance audio between front and rear, and even add a subwoofer for extra bass.
- Maximum Power Output – Power up your music. The GM-A6704 cranks out an impressive 1,000 watts of max power output creating dynamic and impactful sound reproduction, with 60 watts RMS x 4 at 4 ohms (190 watts RMS x2 in bridged mode).
- Efficiency – The Pioneer GM-A6704 boasts a Class AB design, balancing efficiency and performance, ensuring optimal power usage for a reliable audio experience without excessive heat generation.
- Low Distortion – With minimized crossover distortion, this amplifier guarantees a clean and distortion-free audio output, preserving the integrity of the source signal for high-quality sound reproduction.
- Tone Control – Designed with variable high and low-pass filters, control the range of frequencies the amplifier sends to its speakers to enhance the sound based on music type and genre. Tailor your listening experience and enjoy your ride.
I was reading that these Brazilian amps ain't to good and there made in China. What about this one. I want one thats gonna give me good ...
They're decent, solid little amps. We used to use Pioneer all the time, they were our go to because the price was decent and the quality was good.
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“Review: Pioneer GM-A6704 4” · Channel Bridgeable Amplifier
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