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 Coupe (hatchback), 2-Door Convertible
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | rear hatch cargo area (coupe) |
|---|---|
| Outer bounding box | Without T-tops to store: 37"W x 13"H x 7"/12"D. With T-tops to store: 40"W x 8"H x 8"/17"D. |
| Known obstructions | STORED T-TOP PANELS ARE THE OBSTRUCTION, and they do not merely shrink the space — they change its shape. Storing the tops costs five inches of height (13" down to 8") while giving back width and depth, which reads as the tops lying flat and leaving a lower but longer slot rather than simply eating a corner. Design to the WITH-T-TOPS figures if the car has them and you ever intend to remove them, because a box built to the 13" height leaves the panels nowhere to go. On both readings use the SMALLER depth figure (7" without tops, 8" with) for a full-height box, per the catalog rule on paired depths. |
| Usable volume estimate | 1.2 ft³ |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | Compact powered subwoofer — the source's own suggestion, and the honest recommendation given 8-13" of available height |
|---|---|
| Box type | powered enclosure |
| Location | rear cargo area |
| Subwoofers | 1x10" shallow-mount sealed, built to the WITH-T-TOPS envelope if the car has them |
|---|---|
| Box type | sealed |
| Location | rear cargo area |
| Subwoofers | Custom fabrication only. The published envelope is roughly 2 ft3 raw at best, so a competition build here means giving up the T-top storage and probably the cargo floor — measure your own car first |
|---|---|
| Box type | custom |
| Location | rear cargo area |
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 | 6-3/4" either way, but they are NOT the same speaker. BASE cars have a 6-3/4" full-range. MONSOON cars have a proper component set — a 6-3/4" woofer that is 2 OHM, plus a separate tweeter mounted in the same part of the door. Both accept same-size, 6-1/2" or 5-1/4" replacements. |
|---|---|
| Known obstructions | AN ADAPTER BRACKET IS REQUIRED FOR EVERY WOOFER, base or Monsoon — not optional on this car. You must also CUT OUT THE BACK of the plastic cup or mounting bracket to fit either a full-range speaker or a component woofer into the larger opening. And the door-panel removal procedure itself VARIES DEPENDING ON WHETHER THE CAR HAS MANUAL OR POWER WINDOWS AND DOOR LOCKS, so a generic instruction set will not match every Firebird. Tools: panel tool, Phillips screwdriver, socket wrench, extension, 1/4" socket, 7mm socket, shop rag. |
| Adapter bracket needed | Yes — required for each woofer, plus cutting the back out of the factory plastic cup |
| Tweeter | MONSOON CARS ONLY — mounted in the same part of the door as the woofer, as part of a factory component set. Base cars run a single full-range speaker with no separate tweeter. |
| Factory speaker size | None — this is a two-door. Rear speakers live in the rear side panels, and on some coupes additionally in the cargo area (see other_speaker_locations). |
|---|---|
| Known obstructions | n/a |
| Adapter bracket needed | n/a |
| Factory amp / premium audio | The top system is the 500-WATT MONSOON setup, which debuted in 1997 and ran with 8 and eventually 10 speakers — the source rates it as genuinely impressive for its era. Base cars run full-range speakers with no component sets. THE MONSOON SYSTEM IS AMPLIFIED AND CROSSED OVER, and that is the defining integration fact on this car: what looks like a full-range speaker in the rear side panel is actually part of a component system fed a crossed-over signal. Its front woofers are also 2 OHM rather than 4. |
|---|---|
| Adding subs without a head-unit swap | Yes, and given how tight the cargo area is, a compact powered sub is the source's own practical suggestion. Note that on a Monsoon car, replacing the rear side-panel speakers with conventional models requires dealing with the factory amp regardless of what you do about the head unit. |
| Head unit | No replacement needed |
THE CARGO SPACE ON THIS CAR DEPENDS ON WHETHER YOU HAVE T-TOPS TO STORE, and the source publishes two different envelopes for it — the only vehicle where removable roof panels change the figures. WITHOUT T-tops to store: 37"W x 13"H x 7"/12"D. WITH T-tops: 40"W x 8"H x 8"/17"D. Its own summary of the problem is exact: the top has to go somewhere on sunny days, and that somewhere is about where you would install a large enclosed subwoofer. Note that BOTH figures are small by our standards — 13" of height at best and 7-17" of depth. A compact powered sub is the realistic answer for most owners, and the source offers exactly that.
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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.