What we researched for this specific generation: where an enclosure actually fits, what the factory speakers are, how the factory audio is wired, and which real builds and commercial products exist for it. Confidence badges say how well each figure is sourced — this is research, not manufacturer spec.
Body styles covered: 2-Door, 4-Door (Unlimited)
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | rear cargo area |
|---|---|
| Outer bounding box | No independently measured raw cavity envelope found beyond the real 12" ported build reference. UPDATE 2026-10-02 — Jeep's own 2018 Wrangler (JL) spec sheet: 45.0" between wheelhouse interior trim; liftgate opening 41.1" (minimum) to 47.9" (maximum) wide and 35.7" (minimum) to 36.0" (maximum) high; liftover 29.7"; SAE cargo volume 31.7 cu ft rear seat upright, 72.4 cu ft folded. CAVEAT: the sheet's cargo rows are not labelled by body style (its legroom rows are), so these are believed to be the Unlimited figures but the sheet does not say so; model year 2018 only. Jeep publishes no floor length. Vehicle-specific enclosure catalogues; published box footprints are lower bounds on the cavity, not the cavity: NET Audio '2018-up Jeep Wrangler JLU Unlimited Sub Box Medium Downfire Sealed': 38 x 19 x 16 in (as printed; axes not labelled), 3.51 ft3, behind seat, tight against the back of the seat, almost side to side between the fenders, up to where the floor hinges up; NET Audio '2018-up Jeep Wrangler JLU Unlimited Sub Box Shallow Downfire Sealed': 38 x 7 x 16 in (as printed; axes not labelled), 1.12 ft3, behind seat. Vehicle-specific enclosure catalogues; published box footprints are lower bounds on the cavity, not the cavity: Ground Shaker 'BLACK 10" DUAL SEALED SUB BOX, FITS 07-22 JEEP WRANGLER 4-DOOR': Height 13 1/4", Length 49", Top Depth 11", Bottom Depth 12 1/4" (labelled by Ground Shaker), 1.97 FT^3 total; 0.98 FT^3 per subwoofer, FITS BEHIND REAR ROW SEAT [only 2018-2022]. |
| Known obstructions | None specifically documented beyond the confirmed dimension change from the JK generation. |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | 1x10" sealed side-firing (named options: Skar Audio VD-10 D2-loaded, driver or passenger side; or BRP/American Sound Bar enclosure sized for a Rockford Fosgate R2D2) — JK-specific enclosures do NOT fit this generation |
|---|---|
| Box type | sealed, vehicle-specific |
| Location | trunk, side-firing mount |
| Subwoofers | 1x12" ported custom (documented 2021 Unlimited build) or 1x12" swing-gate weatherproof (named option: Stinger, spans JK+JL) or keep/upgrade the factory Alpine 10" QVC sub |
|---|---|
| Box type | ported, sealed swing-gate, or factory QVC system |
| Location | rear cargo area or swing-gate/tailgate mount |
Sizes and depths below are what research turned up for this generation. Confirm against your own vehicle before cutting or ordering — trim levels vary.
| Factory speaker size | SPECIFIC, CONFIRMED FINDING, genuinely different from the JK's 6.5": Jeep's own factory door speaker on this generation is 4" (Jeep measures 'ear to ear' to get a stated 4.5") — a much smaller factory speaker than the prior generation, meaning a straight 6.5" upgrade requires cutting new mounting holes and fabricating brackets, not a simple swap. LOCATION: Metra's JL install pages (2018.5-2023) put this 4" factory opening in the LOWER DASH, not the door ("factory 4-inch opening to accommodate the upgraded 6.5-inch speaker", lower-dash pods JP-1014), and Metra's JL kits list no door-mounted speaker. 6.5" is the replacement kit size there (Metra's own install text calls the same speaker 6"); Metra's 2024-up pages state no factory lower-dash size. |
|---|---|
| Known obstructions | Installing a 6.5" speaker requires cutting new holes and brackets — a confirmed generation-specific difference from the JK, which accepted 6.5" natively. |
| Adapter bracket needed | yes for 6.5" upgrades (cutting required) |
| Tweeter | Dash — Metra's JL kits list a "Pair of 1″ front dash tweeters" that replace the factory tweeters on adapter plates 82-3016 (2018-2023 kits; the 2024-up kits list the same). No source places it in the A-pillar. Distinct from the overhead soundbar speaker. |
| Factory speaker size | not found — no maker or kit source gives a factory rear-door speaker. Metra's JL kits (JP-PPKT-3 and JP-PPKT-4 for 2018-2023, JP-PPKT-1 and JP-PPKT-2 for 2024-up) list no rear-door speaker; the rear speakers they replace are in the overhead soundbar. |
|---|---|
| Known obstructions | 2-door body style has no rear doors |
| Adapter bracket needed | unconfirmed |
| Tweeter | Rear soundbar-area equivalent, per the aftermarket kit's 'front and rear' scope — exact stock diameter not independently confirmed. |
| Factory amp / premium audio | Alpine premium sound system (available trims): includes a factory 10" QUAD VOICE COIL subwoofer — a genuinely unusual, high-spec factory driver (QVC subs are typically chosen for wiring flexibility across multi-amp setups) worth noting as a substantial factory system, not an afterthought. |
|---|---|
| Adding subs without a head-unit swap | CRITICAL, COMPATIBILITY WARNING confirmed via retailer/forum sourcing: the popular Alpine PSS-24WRA aftermarket sound system upgrade is explicitly NOT compatible with the factory Alpine premium sound system, despite both being Alpine-branded — a genuine, easy-to-miss gotcha since 'Alpine upgrading Alpine' sounds like it should obviously work. Verify which factory system is present (base vs. Alpine premium) before recommending any aftermarket Alpine kit. |
| Head unit | No replacement needed |
Current, generation-specific reference build confirmed: a 2021 Wrangler Unlimited fitting a 12" subwoofer in a large ported enclosure in the rear cargo area. Real cargo-dimension confirmation was not found independently for this generation specifically — the JK companion page's own multi-location data (rear cargo, under seat, wheel-well) was NOT assumed to carry over, since commercial sourcing confirms JK-specific enclosures do not fit JL due to a genuine cargo-area dimension change.
Outside links. Some are commercial products, some are owner builds posted on forums — the label says which. We do not endorse any of them.
Each link opens the tool with this vehicle already selected.
Measure your own vehicle. Trim levels, factory subwoofer options, and mid-generation changes all move these numbers, and a box cut to a researched figure that does not match your truck is wasted wood. Where a badge reads Unconfirmed, treat the value as a starting point for your own measurement, not as an answer.