2012-2018 Ford Focus 3rd Gen — 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: 4-Door Sedan, 5-Door Hatchback

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.

Trunk Likely

Locationpassenger side cargo area (hatchback) or trunk (sedan) — genuinely different spaces by body style
Outer bounding boxNo independent trunk/cargo WxH found — hatchback product proxy: single 10" sealed, 500W RMS custom-fit
Known obstructionsBody style matters more than most vehicles here — sedan trunk and hatchback cargo area should not be treated as one uniform shape
Usable volume estimate1 ft³

Starting points

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

Budget

Subwoofers1x10" sealed, 500W RMS (hatchback-specific)
Box typesealed
Locationpassenger side cargo area (hatchback) or trunk (sedan)

Enthusiast

Subwoofers2x10" ported, dual 4" ports
Box typeported
Locationtrunk/cargo area

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 Solid

Factory speaker size6.5" — same size across both sedan and hatchback body styles. Real, confirmed on the Sony 10-speaker premium system: 6.5" woofer PLUS a 1" tweeter in each of all 4 doors (not just front) — a real, complete component layout, not a simple coaxial.
Known obstructionsNone specifically documented
Adapter bracket neededunconfirmed
TweeterFront doors (in-door mount, not A-pillar) — real, named OEM replacement part exists (eBay: '2012-2018 Ford Focus Front Left Door Tweeter Speaker').

Rear doors Solid

Factory speaker size6.5" (sedan) — same size confirmed consistent throughout this generation. Real, confirmed: Sony 10-speaker system's 1" tweeter-per-door layout extends to rear doors too.
Adapter bracket neededunconfirmed
TweeterRear doors, in-door mount

Factory audio integration

Factory amp / premium audioSony 10-speaker premium system confirmed: 6.5" woofer + 1" tweeter in all 4 doors, plus a 3.5" center-dash speaker with its own 1" tweeter (5 tweeters total). Base non-Sony trim breakdown not independently confirmed.
Adding subs without a head-unit swapConfirmed straightforward — trunk-based builds don't touch the head unit
Head unitNo replacement needed

Known integration products

Mounting locations

Trunk Likely

Real specific data across hatchback and sedan: NVX custom-fit single 10" sealed for the 5-door hatchback specifically (500W RMS, passenger side of cargo area); a real custom dual-10" build (35"W x 15"H x 28"/25"D, dual 4" ports); Harmony single 12" loaded box (19.6875"W x 15.75"H x 12.5"/14.875"D, tuned 33Hz, 300W RMS — same enclosure family/dimensions as the Ford Fusion's Harmony box, likely the same generic product line reused across compatible Ford trunk sizes rather than confirmed platform-sharing).

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.