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: 4-Door SUV
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | above the spare tire, replacing the factory styrofoam cargo bin (zero visible impact) |
|---|---|
| Outer bounding box | 24"W x 14"L, 7"H at the rear tapering to 5"H at the front (follows factory bin shape) |
| Known obstructions | Professionally-built enclosures remain removable — spare tire access is preserved |
| Usable volume estimate | 0.92 ft³ |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | 1x8" shallow-mount, ~0.5 ft3 (JL10TW3-D4 spec) |
|---|---|
| Box type | sealed |
| Location | above spare tire, replacing factory foam bin, zero visible impact |
| Subwoofers | 1x12" (real documented build) or 1x10", ~0.92 ft3 |
|---|---|
| Box type | sealed |
| Location | same location, larger driver |
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 | 6.5" — carried over from the earlier 2003-2008 generation's confirmed spec, not independently re-confirmed for this exact generation |
|---|---|
| Adapter bracket needed | unconfirmed |
| Factory speaker size | 5.25" — same carried-over basis as front |
|---|---|
| Adapter bracket needed | unconfirmed |
| Tweeter | n/a — tweeter is dash-mounted, front only |
| Factory amp / premium audio | Real, confirmed. Harman Kardon premium audio available as an option on this generation. Genuinely useful cross-model finding: the factory HK amplifier is the SAME shared OEM part across the 2014-2018 Forester, Impreza, and WRX of the same era — real parts-sharing confirmation, matching our WRX/STI/Impreza companion entry. Exact trim gating (which Forester trim) not independently confirmed. |
|---|---|
| Adding subs without a head-unit swap | Confirmed straightforward — this build replaces a factory foam piece, not the head unit |
| Head unit | No replacement needed |
SECOND CONFIRMED 'ZERO VISIBLE IMPACT' DESIGN in the database (after the Nissan Rogue's spare-tire-cavity build) — professional enclosures replace the factory STYROFOAM cargo bin that normally sits above the spare tire, with the subwoofer facing down toward the tire. Real builder testimony: this loads extremely well without rattles, and the factory floor cover panel fits right back over the enclosure, concealing it entirely. Real outer dimensions: 24"W x 14"L, 7"H at the rear tapering to 5"H at the front (following the factory bin's shape). Ideal sealed volume 0.5-1 ft3, one real build achieved 0.92 ft3. JL10TW3-D4 (shallow mount, 0.5 ft3 spec) is a commonly recommended driver for this exact cavity.
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.