2005-2010 Scion tC Subwoofer Box Fitment

2005-2010 Scion tC 1st Gen (ANT10) — 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: 2-Door Hatchback (Liftback)

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 Solid

Location	trunk
Outer bounding box	Real, rich, multi-source data — this entry's prior note said the Crutchfield source declined to publish dimensions; real commercial sourcing fills the gap cleanly. Dual-10" box: 46.25"W x 14.25"H x 11.125"D, 8" mounting depth, 0.95-0.97 ft3 total. Dual-12" alternative: 1.9 ft3. Dual-10" alternative config: 1.5 ft3. Real, useful install detail: the enclosure contours to the trunk panel curves, has notches to preserve use of the factory cargo cover, and installs through the existing trunk opening with NO metal cutting required.
Known obstructions	None beyond normal fitment — genuinely easy install per the no-cutting confirmation above
Usable volume estimate	0.97 ft³

Starting points

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

Budget

Subwoofers	Powered sub in the cargo area — the source's own suggestion for anyone who wants to keep the space usable
Box type	powered enclosure
Location	rear cargo area

Enthusiast

Subwoofers	1x10" or 1x12" sealed, built to measurements taken from your own car since the source publishes none
Box type	sealed
Location	rear cargo area

Competition

Subwoofers	Custom build — measure first. No published envelope exists for this car, so a competition-scale plan cannot be sized from this page alone
Box type	custom
Location	rear 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 Likely

Factory speaker size	6-3/4" woofer, 4 OHM, low in the door panel. BUT THE PRACTICAL ANSWER IS 5-1/4" COMPONENTS, not a same-size swap — see known_obstructions, because two separate constraints push you there.
Known obstructions	TWO CONSTRAINTS NARROW YOUR OPTIONS SHARPLY, and this is the single most important thing on this page. First, the source describes the mounting height — the gap between the front of the speaker and the door panel — as VERY SHALLOW. Second, the factory opening is oversized, so a mounting bracket is required regardless. Between them, Crutchfield's own conclusion is that replacement options are mostly limited to 5-1/4" COMPONENT sets, with only a few 5-1/4" full-range speakers fitting. Do not buy a deep 6-3/4" driver for this door expecting it to clear. Also: the woofers are RIVETED to the door and the rivets must be drilled out with a 1/8" bit. Panel removal order: pry the sail panel at the top, open the screw cover behind the door release handle and remove that screw, pry the front piece off the door pull handle and remove the two screws behind it, then work the edges with a panel tool.
Adapter bracket needed	Yes, mandatory — the factory opening is oversized and the factory mounting is riveted. A wiring harness adapter is also needed.
Tweeter	On the door, in the mid-line adjacent to the door lock panel just under the window opening — held to the door by a single screw through its bracket. Easy to get to, which is exactly why the source recommends going with components rather than full-range here.

Rear doors Likely

Factory speaker size	None — the tC is a two-door. Its rear speakers live behind the rear side panels (see other_speaker_locations).
Known obstructions	n/a
Adapter bracket needed	n/a

Factory audio integration

Factory amp / premium audio	THIS CAR HAS A FACTORY AMPLIFIER even in standard form — a 160-watt (peak) unit driving the 6-speaker Pioneer system, alongside a flip-up AM/FM/CD head unit with MP3 playback and an auxiliary input jack. That distinguishes it from both xB generations, which have no amp at all. There was also an option to add a factory subwoofer, which came with its OWN separate 35-watt amplifier. So an optioned tC can have two amplifiers in it. Establish which system your car has before ordering: standard 6-speaker, or 6-speaker plus the powered sub in the cargo cavity.
Adding subs without a head-unit swap	Yes. On a car without the factory sub option, a line-output converter and an outboard amp is the standard route. On a car with it, the factory 35-watt amp is the limiting factor and is best bypassed rather than worked around.
Head unit	No replacement needed

Known integration products

A 160-WATT FACTORY AMPLIFIER IS PRESENT ON THE STANDARD SYSTEM. No vehicle-specific amp-bypass or AmpPRO-style interface is named by the source for this car, so a universal high-level-input line-output converter is the documented path — but tap it with the factory amp in mind rather than assuming a head-unit-direct signal.
If the car has the optional factory subwoofer, its 35-watt amplifier is the bottleneck. The source recommends replacing that amp along with the woofer if you upgrade the location at all. For meaningful output, skip the moulded cavity and build in the cargo area instead.
THE FACTORY SUB IS 2-OHM. Fitting a 4-ohm replacement driver into that cavity on the factory 35-watt amp will make an already-underpowered location quieter still — this is the low-impedance trap documented on other vehicles covered here (Honda Civic Premium, Nissan Sentra rear deck, Kia Optima Harman Kardon, Ford Fusion Sony), and it is the opposite of the first-generation xB's 13-ohm tweeter, which gets louder when replaced with 4-ohm.
FRONT DOORS ARE DEPTH-LIMITED: mounting height is described as very shallow and the opening is oversized, so plan on 5-1/4" components with an adapter bracket. Rivets must be drilled out with a 1/8" bit.
REAR SIDE PANELS ARE ALSO DEPTH-LIMITED, with minimal clearance between the panel and the top of the speaker. Check the mounting depth of any 5-1/4" you are considering against that clearance before ordering.
Factory tweeters mount on a single-screw bracket that no aftermarket part replaces — a bracket has to be fabricated, and a universal backstrap cut to size is the documented workaround.

Mounting locations

Trunk Likely

rear cargo area behind the rear seat (no metal cutting)

The source states there is plenty of room in the storage area for a subwoofer enclosure but DOES NOT PUBLISH DIMENSIONS for this car — unusually for a Research Garage article. Measure your own before cutting wood. What it does document precisely is the optional factory subwoofer's home: a moulded cavity to the RIGHT OF THE SPARE TIRE, which is worth knowing because it tells you where the usable floor space actually starts.

Build it for this vehicle

Design a box for this vehicle — Enclosure volume, port tuning, and a cut sheet.
Check door speaker fitment — Whether a given speaker physically fits your doors.
Plan a door panel — Custom panel layout 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.