Subwoofer box for a Ram 1500 or 2500
A Ram cab is wide, and the space under the rear seat of a Crew Cab is one of the roomiest in any truck — but it is low. The box that fits is long and flat, and the subs have to be shallow enough for it.
Where the sub goes, by cab
- Crew Cab. The rear seat cushion flips up; underneath there is room for a long, low box with two subs. On some years the rear floor has built-in storage bins that change the shape of the space — measure with them in place.
- Quad Cab. The rear seat area is shorter, so the box under it is smaller: one shallow 10″ or 12″, or two 8″.
- Regular cab. A thin box behind the seat, with shallow subs, angled to the seat back.
- Ram 2500 / 3500. The same layouts; brackets and storage differ by year. Measure your truck.
Some trims come with a premium audio system that already includes a subwoofer — check before you plan the space.
Pick a sub for this spaceThe calculator opens with the vehicle and the space from this guide and lists the subs that fit there, each with its box. Then adjust the size to your own vehicle.
Example: under a Crew Cab seat
Say the space is 52″ wide, 12″ front to back and 10″ high. With ¾″ walls the inside is 50.5 × 10.5 × 8.5″ — about 2.6 ft³ gross. That is enough for two shallow 12″ subs sealed (0.75–1.5 ft³ each by the sub) or two 10″ with room to spare. For one 12″ ported, 1.5–2.5 ft³ net plus a folded slot port is possible, but tight at 8.5″ inside height.
Cab gain and what it changes
The cab lifts the deep bass, so a sealed box sounds deep here and saves space. The buttons in “Pick a sub for this space” above open the calculator with this already set: the vehicle, where the box goes and the size of the space.
Build tips
- Leave the sub its recommended clearance if it fires down at the floor.
- Bolt the box to the seat brackets or the floor so it cannot move.
- Fuse the power wire within 18″ of the battery.
Design it for your Ram
Enter the measured space, pick your sub and compare sealed and ported; the calculator checks that everything fits and gives you drawings, the cut list and DXF. See also F-150 boxes and under-seat boxes.
Model it for your own subResponse in your car, cone excursion and port air speed — free, no signup.Open the calculator →FAQ
Where does a subwoofer go in a Ram 1500?
In a Crew Cab, under the rear seat: flip the cushion up and a long, low box fits underneath. Some years also have storage bins in the rear floor that limit the space — measure them. In a Quad Cab the space is smaller; in a regular cab only a thin box behind the seat fits.
How big a box fits under the rear seat of a Ram Crew Cab?
Often around 2.5 ft³ gross in a low, wide box — enough for two shallow 10″ or 12″ subs sealed. The inside height decides which subs fit, so check their mounting depth.
Is a Ram 2500 different?
The idea is the same — under the rear seat in a crew cab, behind the seat in a regular cab — but brackets and storage differ between years. Measure your own truck.
Will a ported box fit under a Ram seat?
Sometimes, with one 12″ and a slot port along the box, but the low height makes the port long and folded. In a truck cab a sealed box usually gives deep enough bass in less space.