Every subwoofer we've reviewed so far assumes you have several inches of depth to spare behind the mounting surface. The Kicker CompRT 6.75" assumes you don't: a mounting depth under three inches, built to fit under a seat or behind a back bench, with dual 4-ohm voice coils and 150W RMS (300W peak) handling, at $129.99 (down from $149.99).
This is also the first dual voice coil (DVC) subwoofer in our lineup, every marine sub we've covered elsewhere in this batch runs a single voice coil. That's a real wiring difference worth understanding before you plan an amp connection.
Key Takeaways
- Mounting depth under 3 inches, shallow enough for under-seat or back-bench installs where a standard subwoofer physically won't fit.
- Dual 4-ohm voice coils (4 DVC), the first DVC subwoofer we've covered, offering more wiring flexibility (series, parallel, or independent) than the single-coil KM-series subs.
- 150W RMS / 300W peak, a real power ceiling for the shallow form factor, not a token amount.
- Forced-Air Cooling technology is stated to run the sub 20 percent cooler than Kicker's prior design, relevant for sustained high-volume use.
- SoloKon technology integrates the cone and vented back brace into a single unit, aimed at both cooling and reducing distortion.
What Dual Voice Coil Actually Changes
A single voice coil sub has one set of terminals and one fixed impedance. A dual voice coil sub has two separate coils, each independently wired, giving you options: wire them in series for a higher combined impedance, in parallel for a lower one, or run them independently off different amp channels entirely. That flexibility matters most if you're running multiple subs off one amp and need to land on a specific total impedance your amp is rated for, something the single-coil KM10 and KM12 don't offer.
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Feature Walkthrough
Ultra-Thin Mounting
Under 3 inches of mounting depth, with a 5-5/8" cutout. Kicker specifically markets this for under-seat and back-bench installs where a standard-depth sub has no available space.
Forced-Air Cooling
An engineered cooling system Kicker states runs 20 percent cooler than the prior CompRT generation, relevant since a shallow enclosure typically has less airflow and thermal mass to dissipate heat naturally.
SoloKon Cone-to-Brace Integration
The cone joins directly to a vented back brace as a single integrated unit, a design aimed at both cooling the motor and reducing the kind of distortion that comes from cone flex under load.
Build Details
A red double-stitched bond joins the Santoprene surround to the polypropylene cone, a cosmetic detail that also reinforces the seam under repeated flex.
Installation Notes
No frequency response figure is published on this specific listing, unlike the KM-series and MW-series subs we've covered, which both state a range. If frequency response at the low end specifically matters to your build, confirm that detail directly with Kicker before ordering, rather than assuming parity with the other subs in this catalog.
Amplifier Pairing
At 150W RMS with dual voice coils, your final wired impedance depends on how you connect the two coils. Confirm your amp's rated impedance range and decide series versus parallel wiring based on that, rather than assuming a single "correct" configuration. This is general DVC wiring guidance, not a specific Kicker-confirmed pairing.
Who It's For
Choose the CompRT 6.75" specifically when mounting depth is your real constraint, an under-seat install, a shallow back bench, or any cavity that rules out a standard-depth subwoofer. If depth isn't limited, the KM10 or KM12 give you a stated frequency response spec and simpler single-coil wiring for a comparable price.
Honest Cons
No published frequency response figure on this listing, a gap compared to the other subs we've reviewed — confirm directly if that spec matters to your decision.
DVC wiring adds a decision point that single-coil subs don't require. If you're not comfortable choosing between series and parallel wiring, factor in that extra step.
150W RMS is modest next to the MW-series' 225-450W range, a real tradeoff for the ultra-thin form factor.
Frequently Asked Questions
How thin is "ultra-thin," exactly?
Under 3 inches of mounting depth, shallow enough for under-seat or back-bench installs where standard subwoofers don't fit.
Do I have to wire both voice coils together?
No — you can wire them in series, parallel, or run them independently off separate amp channels, depending on your amp's rated impedance and your system design.
Is this a good fit for a boat with a normal-depth mounting cavity?
It'll work, but if depth isn't your constraint, the KM10 or KM12 offer a published frequency response spec and simpler wiring at a comparable price point.
What does SoloKon technology actually do?
It integrates the cone directly with the vented back brace as one piece, aimed at improving cooling and reducing cone-flex distortion under sustained bass output.
Bottom Line
The CompRT 6.75" solves a real, specific problem, mounting depth, without giving up meaningful power for the size. It's the right subwoofer when a standard-depth sub simply doesn't fit; for boats without that constraint, the simpler single-coil KM-series subs are worth comparing first.