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 Crossover
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | under cargo floor, spare wheel area |
|---|---|
| Outer bounding box | No independently measured raw cavity envelope found — the factory 6" driver's own placement is the best available reference point. |
| Known obstructions | The factory sub sits below a solid cargo floor panel — a confirmed acoustic limitation (muffled output), not just a space constraint. |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | 1x8" or 1x10" powered, T-harness plug-and-play (non-Bose trims, documented approach) |
|---|---|
| Box type | n/a — powered unit, T-harness wiring |
| Location | cargo area |
| Subwoofers | 1x10" or 1x12" sealed, custom-built, wiring tapped BEFORE the factory amp (Bose trims) |
|---|---|
| Box type | sealed, custom |
| Location | cargo area, above the factory under-floor sub location |
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 | not independently confirmed by exact size — search results for this exact generation returned mostly older (1973-2005) Blazer data by mistake; genuinely thinner sourcing for this current generation's exact door speaker size.'s own search ran into the same problem again for tweeter specifics. |
|---|---|
| Known obstructions | None specifically documented |
| Adapter bracket needed | unconfirmed |
| Tweeter | Unconfirmed for this generation specifically; dash-corner (per the related EV) is a plausible but unverified hint. |
| Factory speaker size | not independently confirmed by exact size |
|---|---|
| Known obstructions | Tapping the rear door speakers directly for a signal gives POOR quality; cutting the wires BEFORE they reach the factory amp instead gives a strong, full signal — not every tap point works equally well. |
| Adapter bracket needed | unconfirmed |
| Tweeter | n/a — tweeter (wherever located) is a front-only component on this system |
| Factory amp / premium audio | Bose premium system (available trims): includes the under-spare-wheel 6" subwoofer described above — a confirmed factory system, though owners rate its bass output as genuinely weak due to the solid-floor mounting. Bose (the system maker) lists the Blazer premium system as "8 high-performance speakers" (undated page); it does not say whether a subwoofer is among them, so the forum-sourced 6-inch sub under the spare wheel is neither confirmed nor contradicted. |
|---|---|
| Adding subs without a head-unit swap | Confirmed on non-Bose trims via a documented T-harness plug-and-play install (a complete 'ask me anything' owner thread exists). On Bose trims, cutting wires before the factory amp (rather than tapping at the door speaker) is the confirmed better approach. |
| Head unit | No replacement needed |
Specific factory location confirmed: on Bose-equipped trims, a 6" subwoofer is mounted UNDER THE SPARE WHEEL, under the cargo area floor, driver side. Owner critique: with the spare and trunk cover back in place, you can 'barely hear' the factory sub even standing right at the trunk — mounting a speaker below a solid floor is confirmed to compromise its performance, a real factory-design limitation. For non-Bose trims, a documented T-harness plug-and-play install approach exists, though forum sourcing notes that most available documentation focuses on Bose-equipped cars, leaving firewall access and wire-routing details for non-Bose trims thinner.
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.