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: Quad 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 — real confirmed distinction from Ram 1500: the factory underseat storage on Ram HD is REAL MOLDED SHEET METAL WELDED to the cab floor (per real seat-delete community sourcing), not absent the way it is on the 1500. Goose Gear's seat-delete plate for Ram 2500/3500 spans '2009-Present, 4th & 5th Gen' as ONE continuous product line — i.e. it spans this entry, its Dodge-branded sibling, AND the later 2019-2024 entry. |
|---|---|
| Outer bounding box | Goose Gear 60% plate: ~38.625"W x 42"L. 60% back wall: ~39.125"W (base) / 37.3125"W (top) x 25.125"H. This is the seat-delete PLATE footprint, not necessarily the full underseat cavity depth — treat as a strong proxy, not a confirmed exact cavity match. |
| Known obstructions | None specifically documented beyond the base-vs-top width taper on the back wall |
| Usable volume estimate | 1.85 ft³ |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | 1x10" or 1x12" (same as 1500 of this era) |
|---|---|
| Box type | sealed or ported |
| Location | under rear seat |
| Subwoofers | 2x10" or 2x12" (real named options: Fox Acoustics DQC-112-V-P ported, or Skar Audio 2002-2018 Ram Crew/Quad Cab sealed line), 1.85 ft3 tuned 34Hz |
|---|---|
| Box type | ported or sealed |
| Location | under rear seat, HD may require a seat-lift kit — verify vs. non-HD |
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 | cutout is 6x9", but only ~2" of real mounting depth limits practical replacement size to 6.5" unless using the Mopar-catalog Kicker 6x9" direct-fit part. Real, confirmed: this generation shares the same Alpine/Harman Kardon door architecture as the Ram 1500 of this era (2011-2018 and 2019-2025 entries, same database) — 6x9" woofer + 3.5" tweeter on the premium-audio trims. |
|---|---|
| Max mounting depth | 2 in |
| Known obstructions | Shallow ~2" mounting depth is the binding constraint, not the cutout size — do not recommend a standard-depth 6x9" without checking this |
| Adapter bracket needed | Real, named plug-and-play harness confirmed shared with the 1500 of this era: NET Audio's Dodge Ram Dash Speaker Harness + Tweeter Bracket. Real, genuine Mopar part number confirmed for a cross-trim upgrade: 68043045AD (3.5" Harman Kardon dash speaker) — real owner caution: the 6x9" HK door speakers are 4-ohm vs. the Alpine system's 2-ohm, so swapping doors specifically will cost some volume; the 3.5" dash/tweeter units don't have this impedance mismatch issue. |
| Tweeter | Dash (Infinity-equipped trims) or door-integrated (Alpine/HK trims, in tandem with the woofer) — same location/family as the 1500 of this era. |
| Midrange | n/a in the doors — dash-corner midrange likely present on premium trims matching the 1500's pattern, not independently re-confirmed for this HD-specific entry |
| Factory speaker size | 6x9" cutout |
|---|---|
| Known obstructions | Depth constraint not confirmed for rear doors specifically — verify before assuming it matches the front |
| Adapter bracket needed | unconfirmed |
| Tweeter | n/a — matches the Ram 1500's confirmed woofer-only rear doors |
| Factory amp / premium audio | Same real 3-tier system as the Ram 1500 of this era (base 6-speaker, Alpine, Harman Kardon up to 19-speaker with subwoofer) — not independently re-confirmed as HD-specific but no evidence found of a different HD-only tier. |
|---|---|
| Adding subs without a head-unit swap | Confirmed straightforward — same product ecosystem as the 1500 of this era |
| Head unit | No replacement needed |
CROSS-REFERENCE: research this round returned mostly the same products already documented in the 1500's entries (Fox Acoustics, Skar) — search results explicitly noted products for '2009-up Ram crew cabs' cover this HD range too, suggesting the 1500 and HD trucks shared the same cab/underseat geometry through this era (unlike the current 5th-gen 2019+ trucks, which do have distinct 1500 vs. HD entries already). One HD-specific spec found: Fox Acoustics DQC-112-V-P, 1.85 ft3 internal volume, tuned 34Hz, REQUIRES a 1" seat lift kit (included) for proper fit — this seat-lift requirement may be HD-specific (heavier-duty seat hardware) rather than shared with the 1500.
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.