2011-2018 Ram 1500 4th Gen (DS/D2) — subwoofer box fitment

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

Where a box actually fits

These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.

Quad Crew Cab Likely

Locationunder rear seat — same real architectural note as the 2002-2010 Dodge Ram entry: this truck family doesn't sell a factory/dealer underseat storage-bin accessory the way Ford/GM do (Ram's accessory storage is in-floor, near the doors), so this envelope has to be reconstructed from audio-industry sources rather than confirmed via the storage-accessory industry
Outer bounding boxInferred lower bound from the three real cross-confirmed reference builds: at least enough for a single 12" at 7" mounting depth (Fox Acoustics) or dual 12" sealed (Skar Audio)
Known obstructionsNone specifically documented
Usable volume estimate1.85 ft³

Starting points

Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.

Budget

Subwoofers1x10" or 1x12" sealed/ported
Box typesealed or ported
Locationunder rear seat

Enthusiast

Subwoofers2x8", 2x10", or 2x12" sealed
Box typesealed
Locationunder rear seat

Door speaker fitment

Sizes and depths below are what research turned up for this generation. Confirm against your own vehicle before cutting or ordering — trim levels vary.

Front doors Likely

Factory speaker size6x9" full-range — real, confirmed for this standalone-Ram-brand era.
Known obstructionsNone specifically documented
Adapter bracket neededReal, named commercial adapter/harness: NET Audio's Dodge Ram Dash Speaker Harness + Tweeter Bracket (fits '02-up' Dodge/Ram trucks, spans the brand split).
TweeterFactory: dash corner (Infinity-equipped trims). Real, common aftermarket relocation: enthusiasts consider the A-pillar/sail panel a better tweeter location than the dash for imaging, using 45-degree angled mounts.
Midrangen/a — no separate midrange confirmed on the Infinity system; it's a woofer + dash-corner-tweeter layout

Rear doors Unconfirmed

Factory speaker sizenot independently confirmed for this specific era
Adapter bracket neededunconfirmed
Tweetern/a — not confirmed as a rear-door component

Factory audio integration

Factory amp / premium audioReal, confirmed, closing the gap this entry's prior note flagged. Alpine Premium Audio System confirmed STANDARD on Laramie, Laramie Longhorn, and Limited trims — 9-speaker as the base premium spec (confirmed specifically for 2018). Real step-up: the top trim on Crew Cab/Quad Cab bodies gets a 10-speaker Alpine system adding a subwoofer under the rear seat. This generation used Alpine throughout, distinct from the earlier Infinity-branded system on the pre-2011 companion entry.
Adding subs without a head-unit swapMultiple plug-and-play commercial enclosures exist for this exact fitment without touching the head unit — strong signal this is straightforward on non-premium trims
Head unitNo replacement needed

Known integration products

Mounting locations

Quad Crew Cab Likely

Multiple commercial enclosures confirm this as a well-solved fitment: Fox Acoustics single-12" box (12" sub hole 11.15", mounting depth 7", internal volume 1.85 ft3, tuned 34Hz), Skar Audio dual-12" sealed enclosure, Sound Solutions Audio deep box fitting 2x8" or 2x10". Real, specific, cross-confirmed numbers — higher confidence than a single forum post. Commercial box makers explicitly treat 2002-2018 Quad/Crew Cab as ONE continuous compatible fitment range spanning both this entry and the 2002-2010 Dodge-branded entry — the underseat cavity itself did not change across the 2011 brand split, only the badge did.

Builds and products found for this vehicle

Outside links. Some are commercial products, some are owner builds posted on forums — the label says which. We do not endorse any of them.

Build it for this vehicle

Each link opens the tool with this vehicle already selected.

Before you cut anything

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.