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Rockford Fosgate

Prime R1 8-Inch Marine Subwoofer

$129.99

SKU: RM18D2B

In Stock
In Stock
Ships by Sep 9
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Rockford Fosgate RM18D2B is an 8-inch Prime R1 subwoofer designed for marine, watercraft, and powersports applications. It features a black, color-matched grille and is built to be UV and moisture resistant. This subwoofer can be utilized in sealed, vented, or infinite baffle installations.

Constructed with true marine-grade compliance, the RM18D2B utilizes 100% UV-stable ASA injection molded plastic parts and an injection-molded mineral-filled polypropylene cone body with UV inhibitors. It also features a UV and salt fog resistant Santoprene surround, an ultra-flexible, fully insulated silicone lead wire, and moisture, tear, and fatigue resistant Aramid fiber spider. The unit includes a removable trim ring and grille.
Show original supplier description
The Rockford Fosgate RM18D2B is a black 8-inch Prime R1 subwoofer engineered for demanding marine, watercraft, and powersports environments. Its robust construction ensures durability and longevity, even when exposed to the elements. This subwoofer offers versatility in installation, suitable for sealed, vented, or infinite baffle configurations. Built to True Marine Grade compliance standards, the RM18D2B incorporates several key material and design features. It boasts 100% UV-stable ASA injection molded plastic components and a mineral-filled polypropylene cone body enhanced with UV inhibitors. The surround is made from UV and salt fog resistant Santoprene, while the lead wire is ultra-flexible and fully insulated silicone. A moisture, tear, and fatigue resistant Aramid fiber spider supports the cone, and the subwoofer includes a removable trim ring and grille for aesthetic customization and protection. Key specifications include a nominal impedance of Dual 2-Ohm, a power handling of 150 Watts RMS and 300 Watts Max, and a sensitivity of 85 dB (1w/1m). The mounting depth is 3.6 inches (91.7 mm), and it features a 1.5-inch aluminum voice coil. The subwoofer is CEA-2031 compliant, ensuring its power handling meets industry standards.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandRockford Fosgate
Part NumberRM18D2B
CategoryMobile Electronics

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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