The Kicker 51MSS65 and 51MSS8 are component speakers, tweeter and woofer as separate physical pieces rather than combined into one basket, using the same carbon-fiber woofer cone, 28mm Tetoron tweeter, and Butterworth crossover as the Premium 51MSC coaxial line. Power ratings are identical between the two formats. The component version costs $100 more at every size: $599.99 versus $499.99 at 6.5", $699.99 versus $599.99 at 8".
Same electronics, same power, $100 more, for the ability to mount the tweeter separately from the woofer instead of stacked in one basket.
Key Takeaways
- Identical power ratings to the 51MSC coaxial line: 15-100W RMS (6.5") and 15-200W RMS (8"), same peak figures.
- Same core components: carbon-fiber-infused woofer cone, 28mm Tetoron tweeter, internal Butterworth 12dB/octave crossover, RGBW LED, both grille colors included.
- The tweeter mounts separately, with its own 2" mounting hole and 2-1/8" depth requirement, distinct from the woofer's cutout.
- $100 more per size than the equivalent coaxial 51MSC model, for the separate-mounting capability alone.
- Same cutout diameters as the coaxial line for the woofer itself (5-7/16" at 6.5", 6-9/16" at 8").
What the Extra $100 Actually Buys
Component speakers let you position the tweeter independently from the woofer, useful for directing high frequencies toward a specific listening position, or when the ideal woofer location doesn't have room for an integrated tweeter. Kicker's own description points to "increased mounting options and sonic accuracy" as the component design's benefit. If your install doesn't need that flexibility, the coaxial 51MSC delivers the identical electronics in a single mounting cutout for less.
Check the 51MSS65 → | Check the 51MSS8 →
Feature Walkthrough
Separate Tweeter Mounting
The tweeter requires its own 2" mounting hole at 2-1/8" depth, in addition to the woofer's standard cutout. Plan for two mounting locations per speaker, not one, when laying out a component install.
Shared Electronics
Carbon-fiber-infused woofer cone, 28mm Tetoron tweeter, Butterworth crossover, RGBW LED, and both white and charcoal grilles included, identical to the coaxial 51MSC line's component list.
Power and Impedance
15-100W RMS (200W peak) at 6.5", 15-200W RMS (400W peak) at 8", both at 4-ohm, matching the coaxial version's ratings exactly.
Installation Notes
Because the tweeter mounts separately, this install requires planning two cutout locations per speaker instead of one, plus routing wire between the crossover, woofer, and tweeter. If your dash or hull doesn't have a natural secondary mounting spot near the woofer location, the coaxial 51MSC avoids that added complexity entirely.
Who It's For
Choose the component 51MSS if you specifically want to aim the tweeter independently from the woofer, or your installation location doesn't accommodate an integrated coaxial design. Choose the coaxial 51MSC instead if a single mounting cutout is simpler for your boat and you don't need separate tweeter placement.
Honest Cons
$100 more per size for the same electronics as the coaxial version, only justified if you actually use the separate mounting capability.
More complex installation, with two cutout locations and additional wiring per speaker instead of one integrated unit.
No numbered IP rating published, consistent with the rest of the Premium marine line.
Frequently Asked Questions
Is the 51MSS actually better-sounding than the 51MSC?
The core electronics are identical; any sonic difference comes from the ability to position the tweeter independently, not from different components.
Can I use the crossover from the coaxial version instead?
Each is sold as a matched system; mixing crossovers between the coaxial and component versions isn't confirmed compatible on either listing.
How much extra mounting space does the tweeter need?
A 2" diameter hole at 2-1/8" depth, separate from the woofer's own cutout.
Do both grille colors come included, like the coaxial version?
Yes — both white and charcoal grilles ship in the box, matching the 51MSC's inclusion.
Bottom Line
The 51MSS component speakers deliver the identical Premium electronics as the coaxial 51MSC for $100 more per size, justified only if you actually need to mount the tweeter separately from the woofer. Without that specific requirement, the coaxial version is the simpler, less expensive choice.