"Up to 500 watts" is the headline number on the Kicker KPX500.1, but that figure only applies at 1-ohm. At 4-ohm, the same amp delivers 150W, a real difference worth understanding before you buy based on the number in the product title. It's a compact mono subwoofer amplifier built for tight motorcycle and UTV mounting spaces, weather-resistant, with a 24dB/octave crossover and subsonic filter, priced at $299.99 (down from $329.99).
As an authorized Kicker dealer, we want to walk through exactly what changes at each impedance before you plan a system around the biggest number on the box. Here's the full breakdown.
Key Takeaways
- Power output scales with impedance: 500W at 1-ohm, 300W at 2-ohm, 150W at 4-ohm — three genuinely different numbers depending on your subwoofer's wiring.
- Built specifically for tight spaces: Kicker states it fits under motorcycle fairings, a footprint claim most marine amps in this catalog don't make.
- Includes a 24dB/octave variable low-pass crossover and 24dB/octave variable subsonic filter, both adjustable rather than fixed.
- Weather-resistant, not a numbered IP rating — treat it as splash-resistant, not fully submersible or pressure-washer safe.
- Compatible with the optional CXARC remote bass control, and the DBRC remote if you're running two mono amps or powered subs together.
The Number That Actually Matters: Your Subwoofer's Impedance
A mono subwoofer amp's rated power depends entirely on the impedance it's driving. The KPX500.1 delivers 1x500W at 1-ohm, 1x300W at 2-ohm, and 1x150W at 4-ohm — the same amplifier, three very different real-world outputs depending entirely on how your subwoofer (or subwoofers) are wired. If a subwoofer's spec sheet says "4-ohm," plan around the 150W figure, not the 500W headline number on this amp's product title.
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Feature Walkthrough
Compact Footprint
Kicker explicitly markets this as fitting under motorcycle fairings — a fitment claim specific to tight powersports mounting spaces, not something stated on the marine amps we've reviewed so far.
Crossover and Subsonic Filter
Both the 24dB/octave low-pass crossover and 24dB/octave subsonic filter are variable, letting you tune the exact frequency range sent to your subwoofer and protect it from frequencies below its safe operating range.
Remote Bass Control
The optional CXARC remote lets you adjust bass level from the handlebars or dash without reaching for the amp itself. If you're running two mono amps or powered subwoofers together, the DBRC remote controls both from a single knob.
Dynamic Power
750W dynamic power is rated separately from the continuous RMS figures above — a short-term headroom number, not a sustained output you should plan a system around.
Amplifier-to-Subwoofer Matching
Since we haven't yet reviewed a Kicker subwoofer in this batch, match this amp's output at your subwoofer's actual impedance: a 4-ohm sub gets 150W from this amp, a 2-ohm sub gets 300W, and a 1-ohm sub (or two 2-ohm subs wired to a 1-ohm total load) gets the full 500W. Confirm your specific subwoofer's impedance and RMS rating before wiring, rather than assuming the 500W headline figure applies.
Who It's For
Choose the KPX500.1 if you're building a compact powersports subwoofer system, on a motorcycle, UTV, or ATV, where mounting space is tight and you want flexibility to run the sub at whatever impedance fits your build. It's not the amp for a full-range speaker system — this is a dedicated mono sub amp only.
Honest Cons
The 500W headline number only applies at 1-ohm. Most subwoofers run at 4-ohm or 2-ohm, where this amp delivers meaningfully less.
Weather-resistant, not a numbered IP rating. Treat it as splash-resistant, not fully sealed against submersion or pressure washing.
Mono/subwoofer only. This doesn't replace a full-range amp for speakers — it's a dedicated addition to a system that already has one.
Frequently Asked Questions
Does the KPX500.1 really put out 500 watts?
Only at 1-ohm. At 2-ohm it's 300W, and at 4-ohm it's 150W. Match the number to your actual subwoofer's wired impedance.
Will this fit under a motorcycle fairing?
Kicker markets it specifically for that use case, with an extremely compact footprint compared to typical full-size amplifiers.
Can I control bass level remotely?
Yes — the optional CXARC remote handles single-amp bass control; the DBRC remote controls two amps or powered subs from one knob.
Is this amp fully waterproof?
No — it's described as weather-resistant, not submersible or pressure-washer rated. Mount it somewhere protected from direct water exposure.
Bottom Line
The KPX500.1 is a genuinely compact, flexible mono sub amp for powersports builds, but the 500W name on the box is an upper bound at 1-ohm, not a guarantee. Match your subwoofer's real impedance to the correct power tier before you plan the rest of your system around it.