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: Extended Cab, Crew Cab
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | underseat, crew cab |
|---|---|
| Outer bounding box | Aftermarket full-width lockbox (storage-industry product, real cross-check): 13.5"D x 42"W x 7"H (~1.1-1.2 ft3 usable). Older factory bins (pre-refresh): two separate bins, ~8"W and ~12"W, both ~14"D — smaller and split, not full-width. Vehicle-specific enclosure catalogues; published box footprints are lower bounds on the cavity, not the cavity: SRQ Customs 'Chevy Colorado / GMC Canyon Subwoofer Enclosure 10"': 50 x 12 x 12 in (as printed; axes not labelled), 0.8 ft3, under rear seat (replaces factory bar and tub); crew cab only; SRQ Customs 'Chevrolet Colorado 2015-25 Crew Cab Subwoofer Enclosure': 54 x 16 x 16 in (as printed; axes not labelled), replaces the plastic tray under the back seat in the crew cab models. Vehicle-specific enclosure catalogues; published box footprints are lower bounds on the cavity, not the cavity: Ground Shaker 'BLACK 8" DUAL SEALED SUB BOX, FITS 15-26 CHEVY COLORADO CREW-CAB': Height 7 1/4", Length 42 1/4", Depth 14 1/2" (labelled by Ground Shaker), 0.96 FT3 total; 0.48 FT3 per subwoofer, under rear seat. |
| Known obstructions | Factory layout is split into two separate bins rather than one continuous cavity on earlier trim configurations — matches the 3.5" depth ceiling already confirmed via the audio-specific commercial products in this page |
| Usable volume estimate | 1.1 ft³ |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | 1x10" shallow-mount sealed, 0.6 ft3, includes amp shelf |
|---|---|
| Box type | sealed |
| Location | under rear seat, downfire, max 3.5" depth |
| Subwoofers | 2x10" shallow-mount sealed, 0.45 ft3/sub |
|---|---|
| Box type | sealed |
| Location | under rear seat, downfire, max 3.5" depth |
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 | 6.5" |
|---|---|
| Known obstructions | None specifically documented |
| Adapter bracket needed | no — Crutchfield notes 6.5" replacements come with a mounting plate for factory locations |
| Factory speaker size | 6.5" (same as front, Crew Cab) |
|---|---|
| Known obstructions | None specifically documented |
| Adapter bracket needed | no |
| Factory amp / premium audio | Partial. Optional 7-speaker Bose premium system confirmed specifically for 2015-2018 — the same 7-speaker spec as the 2004-2012 companion page's Bose option, real platform continuity across generations. 2019-2022 continuation not independently re-confirmed, and exact trim gating (LT/Z71/ZR2/Denali) not found. |
|---|---|
| Adding subs without a head-unit swap | Confirmed straightforward — multiple commercial direct-fit products exist |
| Head unit | No replacement needed |
Specific commercial specs across two configs: dual 10" downfire (3.5" mounting depth — restrictive, this is a mid-size truck with less underseat room than the full-size trucks — 0.45 ft3 per sub sealed, fits 8" or 10" shallow-mount only); single 10" downfire with amp space (28 lbs empty, 3.5" depth, 11"x15" amp shelf, 0.6 ft3 sealed). The consistent 3.5" depth ceiling across both products is a useful design constraint specific to this smaller platform — thinner drivers required than on full-size trucks. Skar Audio's Colorado/Canyon Crew Cab dual 8" loaded ported box "was engineered for the 2015-2022 generation, where it drops straight in under the rear seat"; on the 2023-2026 trucks Skar says the factory under-seat area was changed and "usually needs minor modification" — so 2023+ trucks should not be assumed to share this cavity. Skar publishes no outside dimensions on the page read.
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.