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: 5-Door Hatchback
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | below rear dash, slides in through trunk opening |
|---|---|
| Outer bounding box | Custom lowered-floor build: ~40x30" area, ~4.5" tall exterior clearance, trunk floor lowered to a ~6.5" lip |
| Known obstructions | Hatchback shares airspace between trunk and cabin — a real acoustic/structural reason this platform supports larger volume than most sedans at a similar footprint |
| Usable volume estimate | 2 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 | below rear dash |
| Subwoofers | 1x12" sealed, ~2-2.25 ft3 via lowered trunk floor |
|---|---|
| Box type | sealed |
| Location | below rear dash, custom lowered floor |
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 | 6x8" on most trims, but real reported variance to 5x7" ovals on some — Crutchfield itself has shown inconsistent guidance (5.25" rounds recommended on one page) and real owners report physically checking before ordering |
|---|---|
| Known obstructions | Real documented Bose-vs-standard fitment confusion — verify system before ordering |
| Adapter bracket needed | unconfirmed |
| Tweeter | SAIL-PANEL mounted (not in the door itself, not dash) — real, confirmed on 6-speaker (Bose) models, accessible by pulling the sail panel near the mirror. Real, genuine physical constraint: the largest tweeter that fits without cutting the sail panel is around 1/2" — a real, small ceiling worth flagging for anyone planning a tweeter upgrade in the stock location. |
| Factory speaker size | same 6x8"/5x7" variance as front per real owner reports |
|---|---|
| Adapter bracket needed | unconfirmed |
| Tweeter | n/a — tweeter is sail-panel mounted, front only |
| Factory amp / premium audio | Real, specific, with a genuine mid-generation upgrade. Base: 4- or 6-speaker system. Optional premium tier: 7-speaker Bose system that adds a subwoofer. Real step-up confirmed by 2010 (near this entry's end date): the Mazda3 HB GT trim carried a larger 10-speaker Bose configuration — a real spec increase within this generation's run, not a static single system throughout 2004-2010. |
|---|---|
| Adding subs without a head-unit swap | Confirmed straightforward — slides in below the rear dash without removing or modifying any car parts |
| Head unit | No replacement needed |
Why hatchbacks are favored for bass, confirmed rather than assumed: a source states directly that hatchbacks are 'particularly conducive for loud bass since the trunk and cabin share airspace' — a real acoustic/structural reason, not just enthusiast preference. Real spec: 7.00" mounting depth (fits 6"-magnet subs), 9.125"/11.125" mounting diameters (10"/12"), 1.04 ft3/chamber, sealed. Real custom-build note: the trunk floor can be lowered to a ~6.5" lip, leaving ~40x30" of area and ~4.5" tall exterior clearance, yielding roughly 2-2.25 ft3 — genuinely larger volume than most sedan trunks at a similar footprint, which is the hatchback advantage in practice. Sealed is often the only feasible enclosure type here — not enough volume for a proper ported design.
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.