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 Sedan
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | trunk, through existing opening |
|---|---|
| Outer bounding box | Not independently measured — single documented build used 1.37 ft3 ported, 1/2" MDF |
| Known obstructions | None specifically documented |
| Usable volume estimate | 1.37 ft³ |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | 1x10" sealed |
|---|---|
| Box type | sealed |
| Location | trunk |
| Subwoofers | 1x10" or 1x12" ported, 1.37 ft3, tuned 31Hz |
|---|---|
| Box type | ported |
| Location | trunk |
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 | unconfirmed — Crutchfield fit-database coverage confirmed to exist but specific dimensions not surfaced |
|---|---|
| Adapter bracket needed | unconfirmed |
| Factory speaker size | unconfirmed |
|---|---|
| Adapter bracket needed | unconfirmed |
| Tweeter | n/a — tweeter is dash-corner mounted, front only |
| Factory amp / premium audio | Real, clean, matches the same Limited-trim gating pattern found across the rest of our Subaru lineup. Harman Kardon Premium Audio confirmed on the Legacy Limited trim. Exact year-by-year availability within 2015-2019 not independently re-confirmed, but no evidence found of it being dropped for any year in this range. |
|---|---|
| Adding subs without a head-unit swap | Confirmed straightforward — trunk-based builds don't touch the head unit |
| Head unit | No replacement needed |
Real specific build: 1.37 ft3 ported enclosure, tuned 31Hz, 1/2" MDF construction. Earlier Legacy GT Wagon-era product (0.65 ft3, up to 6.95" mounting depth) is shared with the Outback wagon entry of a similar era — same platform, different body style.
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.