1987-1993 Ford Mustang Fox (late) — subwoofer box fitment

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: Notchback (2-Door Coupe), Hatchback (3-Door), Convertible

Where a box actually fits

These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.

Notchback Likely

Locationtrunk
Outer bounding boxNot independently measured — real shape constraint only: square 12" boxes don't fit, wedge-shaped or single 10" square boxes do.
Known obstructionsReal, specific: a square 12" enclosure does not fit this trunk shape — a genuine, checkable constraint from real builder experience, not a guess.

Starting points

Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.

Budget

Subwoofers1x10" sealed, custom-built in the spare-tire-delete space (real documented technique above)
Box typesealed
Locationtrunk, spare-tire-delete area

Enthusiast

Subwoofers1x10" wedge-shaped or custom-conformed, avoiding a square 12" box which real sourcing confirms doesn't fit this trunk shape
Box typesealed, wedge-shaped
Locationtrunk

Door speaker fitment

Sizes and depths below are what research turned up for this generation. Confirm against your own vehicle before cutting or ordering — trim levels vary.

Front doors Likely

Factory speaker sizeReal disagreement across sources, same pattern as the 1979-1986 companion entry: both 6.5" and 5.25" show up in real sourcing. Recorded as a range rather than resolved to one figure — may reflect a real running change within this generation's own span, not necessarily source error.
Known obstructionsSame Fox-platform depth caution as the 1979-1986 companion entry — limited room behind the door panel for large-magnet aftermarket drivers.
Adapter bracket neededunconfirmed
Tweetern/a in the doors — dash-mounted 3.5" speakers, same as the 1979-1986 companion entry

Rear doors Unconfirmed

Factory speaker sizen/a — 2-door body styles only, no rear doors on this platform
Known obstructionsNo rear doors on this platform
Adapter bracket neededn/a

Factory audio integration

Factory amp / premium audioReal, confirmed, NOT the Mach 460 (that system did not exist until 1994 — see our 1994-2004 Mustang entry). This generation's factory premium option was 'Premium Sound' — the same non-Mach lineage as the 1979-1986 companion entry. REAL, SPECIFIC, YEAR-GATED DETAIL WITHIN this entry's SPAN: the amplifier's physical location changed mid-generation — behind/below the radio receiver on 1987-1992 cars, then moved UNDER THE PASSENGER SEAT specifically for 1993 cars. A real, checkable, single-year change worth knowing before assuming where to find the amp for a bypass or tap.
Adding subs without a head-unit swapConfirmed straightforward — trunk-based builds don't touch the head unit or Premium Sound amp regardless of its 1987-1992 vs. 1993 location.
Head unitNo replacement needed

Known integration products

Mounting locations

Notchback Likely

No clean published dimensions found, but a real, useful shape constraint: forum sourcing describes a square 12" box as NOT fitting, recommending a wedge-shaped enclosure instead — a single 10" square box may fit where a 12" square one won't. Real documented builder technique: removing the spare tire and building a custom 10" box from 1/4" MDF in that space.

Hatchback Likely

Not independently re-measured — real, likely-similar cargo geometry to the 1979-1986 companion entry's confirmed 32.7 ft3 (seats folded), since both are the same Fox platform hatchback body, but not independently confirmed identical.

Builds and products found for this vehicle

Outside links. Some are commercial products, some are owner builds posted on forums — the label says which. We do not endorse any of them.

Build it for this vehicle

Each link opens the tool with this vehicle already selected.

Before you cut anything

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.