Product Overview

Description

Built for the 02–16 Ford F-250 Ext Cab, this is Ground Shaker's dual 8" sealed enclosure, and it sits under the rear seat and fires upward. It is a sealed box, so expect clean, tight low end that blends with the rest of the system rather than overpowering it. Each woofer gets its own chamber, which keeps them from fighting each other.

Key Features

  • Vehicle-specific dual sealed enclosure built for the 2002–2016 Ford F-250 Ext Cab
  • Dual 8″ woofers in 2 individual chambers — 0.56 ft³ per subwoofer, 1.12 ft³ total
  • Fits under the rear seat, up firing (removal of jack kit is required)
  • ⅝″ high-quality MDF construction, carpeted in durable trunk-liner finish
  • Sealed with Titebond silicone and glued with Titebond wood glue
  • 2 binding post terminals

Specifications

SKU GS-KF25028B
Application 02–16 Ford F-250 Ext Cab
Woofer Size 2 × 8″
Cutout Diameter 7⅛″
Air Volume 1.12 ft³ total — 2 individual chambers, 0.56 ft³ per subwoofer
Mounting Depth 5½″
Enclosure Type Sealed
Firing Direction Up
Height 5¾″
Length 50¼″
Top Depth 12″
Bottom Depth 9½″
Construction ⅝″ high-quality MDF, carpeted trunk-liner finish
Terminals 2 binding post terminals
Weight 32 lbs
Color Black

Subwoofer option

Add two DS18 SRW8.4 shallow-mount 8" subwoofers — 150W RMS / 300W MAX, SVC 4-ohm, 2.95" mounting depth, 7.12" front-mount cutout per DS18's dimension drawing — and they ship with the box, one per woofer opening. This box is cut 7⅛″ with 5½″ 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+

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.

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