Ground Shaker GS-FB18B Single 8" Sealed Sub Box — Fits 21–26 Ford Bronco (Under Rear Seat)
Enclosure only — subwoofers not included.
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Ground Shaker GS-FB18B Single 8" Sealed Sub Box — Fits 21–26 Ford Bronco (Under Rear Seat)
Product Overview
Description
This Ground Shaker single 8" sealed enclosure is cut for the 21–26 Ford Bronco (Under Rear Seat); it sits under the rear seat and fires forward. Sealed boxes like this favor tight, accurate bass over sheer volume, and the 0.40 cubic feet of air volume suits most 8" subs. Subwoofers are not included, so bring your own or match it with one from the DS18 lineup.
Key Features
- Vehicle-specific single 8" sealed subwoofer enclosure — fits 2021–2026 Ford Bronco (6th Gen)
- Fits under the rear seat, forward-firing design
- 0.40 ft³ air volume
- ⅝" high-density MDF construction, carpeted in durable trunk-liner finish
- Sealed with Titebond silicone, glued with Titebond wood glue
- 1 binding post terminal
Specifications
| SKU | GS-FB18B |
| Application | Ford Bronco 2021–2026 (6th Gen) — under rear seat |
| Woofer Size | 1 × 8" |
| Cutout Diameter | 7⅛" |
| Air Volume | 0.40 ft³ |
| Mounting Depth | 4½" (with a 5" radius magnet) |
| Enclosure Type | Sealed |
| Firing Direction | Forward-firing |
| Height | 9½" |
| Length | 15¾" |
| Width | 12¼" |
| Construction | ⅝" high-density MDF, carpeted trunk-liner finish, Titebond silicone sealed and wood-glued |
| Terminals | 1 binding post |
| Weight | 12 lbs |
| Color | Black |
Subwoofer option
Add one DS18 SRW8.4 shallow-mount 8" subwoofer — 150W RMS / 300W MAX, SVC 4-ohm, 2.95" mounting depth, 7.12" front-mount cutout per DS18's dimension drawing — and it ships with the box, one per woofer opening. This box is cut 7⅛" with 4½" of mounting depth, so the SRW8.4 fits as shipped. Choose "Box only" to buy the enclosure alone.
Box-only option: subwoofers not included. Price is each.
Free shipping on orders $150+
If you have any questions, you are always welcome to contact us. We'll get back to you as soon as possible, within 24 hours on weekdays.
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FAQs
Please read our FAQs page to find out more.
RMS vs. MAX power — which number do I actually care about?
RMS is what your gear handles continuously; MAX is the short burst it can survive without complaint. Match your amplifier's RMS output to your speakers' RMS rating — sizing off the MAX number is how magic smoke gets released.
What does the IP65 rating on DS18 marine gear actually mean?
It's dust-tight and rated against low-pressure water jets from any direction — built for spray, rain, and the occasional wave over the bow, not for full submersion. If something's going somewhere it could sit underwater, that's a different conversation entirely.
How do I match an amplifier to my speakers without guessing?
Add up the RMS rating of everything the amp will power, and pick an amp whose RMS output (at your speakers' impedance — usually 4-ohm) lands close to that total. Undersized is thin sound; wildly oversized is a fast way to blow a voice coil.
Can I mix marine-grade gear into a standard car audio setup, or the reverse?
You can run marine-grade gear in a car — it's just over-built for that environment, no downside besides cost. Running non-weatherproof car audio gear in an open UTV or boat is the direction that causes problems.
What gauge wiring kit do I need?
It scales with your amp's power draw and the length of the run — DS18's OFC kits come in 4-gauge and 8-gauge for a reason. Undersized wiring on a high-draw system is a voltage-drop and heat problem waiting to happen; when in doubt, size up.