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: Regular Cab, Crew Cab, Mega 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 — confirmed distinction from Ram 1500: the factory underseat storage on Ram HD is 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 page (2010-2018) AND the later 2019-2024 page. |
|---|---|
| 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. Vehicle-specific enclosure catalogues; published box footprints are lower bounds on the cavity, not the cavity: Kicker 'RAM Classic-Specific Dual 10" L7T 2-Ohm Enclosure': 58-7/16" W x 7-9/16" H x 16-7/16" D (Kicker's labels; the box is formed to the cab contours), under the back seat; NET Audio '2009-2018 Dodge Ram Crew Cab Sub Box Dual Low Stage 1': 59 x 16 x 8.5 in (as printed; axes not labelled), 1.6 ft3, under rear seat, full width; NET Audio '2009-2018 Dodge Ram Crew Cab Sub Box Dual Tall Stage 1': 60 x 15 x 10 in (as printed; axes not labelled), 2 ft3, under rear seat, full width; seat lifted 1.5 in with included spacers. Vehicle-specific enclosure catalogues; published box footprints are lower bounds on the cavity, not the cavity: Ground Shaker 'BLACK 12" DUAL SEALED SUB BOX, FITS 02-18 DODGE RAM 1500, 2500 & 3500 CREW-CAB & EXT-CAB': Height 8 1/4", Length 55 1/2", Depth 13 3/4" (labelled by Ground Shaker), 0.98 FT^3 (2 chambers), FITS UNDER REAR SEAT. |
| Known obstructions | None specifically documented beyond the base-vs-top width taper on the back wall. Ram HD sheets: 'Rear, under-seat compartment (Crew Cab Only)' is standard on every trim in 2012, 2015 and 2018 — the Crew Cab under-seat cavity holds a factory compartment (consistent with the welded sheet-metal storage described above); 2012 also lists 'Rear, in-floor storage boxes (Crew Cab Only)'. The Mega Cab and Regular Cab list 'Behind the seat' storage instead. Dodge's 2010 sheet lists 'Rear, Under-Seat Compartment (Crew Cab Only)' and 'Rear In-floor Storage Boxes (Crew Cab Only)' as standard on every trim, and gives the Mega Cab the 'largest cargo volume behind rear seat (7.7 cubic feet)', a cab-storage figure, not a box volume. |
| 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" (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. Confirmed: this generation shares the same Alpine/Harman Kardon door architecture as the Ram 1500 of this era (2011-2018 and 2019-2025 pages, same catalogue) — 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 | Named plug-and-play harness confirmed shared with the 1500 of this era: NET Audio's Dodge Ram Dash Speaker Harness + Tweeter Bracket. Genuine Mopar part number confirmed for a cross-trim upgrade: 68043045AD (3.5" Harman Kardon dash speaker) — 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 page |
| 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. Ram's HD sheets show a different HD tier: 2012 and 2015 'Six-speaker' standard on lower trims and 'Nine amplified speakers with subwoofer (surround sound)' optional on mid trims, standard on Laramie and above (2015 also 'Premium speakers (Regular Cab only)'); 2018 'Six-speakers', 'Premium I audio system (reg cab only)' and 'Premium II audio system with subwoofer'. None of the three HD sheets names Alpine or Harman Kardon and none lists anything near 19 speakers, so the 1500's 19-speaker Harman Kardon tier above is not supported for the HD. 2010 (the Dodge-badged year): Confirmed for this model year. Alpine premium system confirmed on Laramie trim, package-dependent at 9 or 10 speakers (10-speaker package adds a subwoofer under the rear seat). Real cross-confirmation: this matches the Alpine finding on the 1500 of the same era and forum sourcing directly describes Alpine as the successor to the older Infinity system — consistent with this truck sitting right at that brand transition. Dodge's 2010 Ram HD sheet: trims ST, SLT, TRX, Power Wagon and Laramie; 'Six-speaker System' on ST, SLT, TRX and Power Wagon; 'Nine Amplified Speakers with Subwoofer (Surround Sound)' optional on SLT, TRX and Power Wagon, standard on Laramie (the press text calls it a '10-speaker surround-sound system'). Dodge prints ONE surround package (nine speakers plus a subwoofer), not a 9-or-10 choice, and names no brand and no subwoofer location — the Alpine attribution above is not on Dodge's sheet. |
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| 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: mostly the same products as the 1500 (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 pages 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.