Spare tire subwoofer box
The spare tire well is the classic hiding place for a sub: the box sits below the cargo floor and the trunk stays flat and usable. The well is small and round, so the box is compact and sealed.
What you give up
The spare tire goes. Carry a tire repair kit and an inflator, and check whether your local rules or roadside plan expect a spare. Some cars already have no spare and come with a kit — then the well is free.
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.
Subwoofers that fit here
Models from our database whose cutout, mounting depth and recommended box (per sub) fit the spot above, deepest bass first. Each link has the specs and a box with dimensions.
Spare tire well: 10″
| Model | Sealed | Ported |
|---|---|---|
| B2 Audio RIOT10 D2 v3 | 0.60 ft³ | — |
| Rockford Fosgate Punch P310D4 (Stage-3, 2004) | 0.81 ft³ | — |
| Hifonics ZXS10D2 | 0.78 ft³ | — |
| Diamond DE104 | 0.57 ft³ | — |
| RE Audio SCX10 D4 v2 | 0.67 ft³ | — |
| Rockford Fosgate Punch P3D2-10 | 0.60 ft³ | — |
| Dayton Audio UM10-22 | 0.53 ft³ | — |
| Sky High Car Audio FXB-10 D4 | 0.60 ft³ | — |
How big a box fits
The calculator draws rectangular and wedge boxes, so fit a square box inside the round well. A well 24″ across holds a square about 17″ on a side; at 8″ deep and ¾″ walls the inside is 15.5 × 15.5 × 6.5″ — about 0.9 ft³ gross. That is enough for one 10″ sealed (0.5–0.9 ft³ by the sub) or an 8″. Corners cut at 45° fit the round well better and lose only a little volume — enter that as extra volume taken in the calculator.
Firing up or down
- Up into the cargo floor: cut a hole in the floor panel or use a grille so the sound gets out and the cone is protected from cargo.
- Down into the well: leave at least the sub’s recommended clearance above the bottom.
Water and heat
Spare wells collect water. Keep the drain plug clear, seal the box, and raise it on rubber feet. Do not block the battery or fuel components that some cars keep near the well.
In the calculator
Choose your body type and the placement “In a sealed trunk (sedan, coupe)” for a sedan or “In a cargo area open to the cabin (hatchback, wagon, SUV)” for a hatch or SUV, enter the box size, pick your sub and check the response, excursion and that the sub’s depth fits. See also net vs gross volume.
Model it for your own subResponse in your car, cone excursion and port air speed — free, no signup.Open the calculator →FAQ
Can a subwoofer go in the spare tire well?
Yes — it is a popular stealth install: the box sits in the well under the cargo floor, and the trunk stays flat. You lose the spare, so carry a repair kit and inflator instead.
What size sub fits in a spare tire well?
Usually one 10″ or 8″ in a sealed box. A typical well about 24″ across and 8″ deep holds roughly 0.9 ft³ gross in a square box — enough for a 10″ sealed.
Sealed or ported in the spare well?
Sealed: the volume is small and a port has nowhere to go. The cargo area or trunk lifts the deep bass, which helps a small sealed box.
Does the sub fire up or down?
Either. Firing up into the cargo floor needs a grille or holes in the floor panel; firing down needs clearance above the bottom of the well. Keep the well’s drain plug clear and the box off any standing water.