WooferGuy is reader-supported. When you buy through an Amazon link on this page we may earn a commission, at no extra cost to you. It never decides what we recommend. How this works.
A good prefab box is the fastest way to get a new subwoofer playing properly. You skip the saw and the glue, and a well-made ported box from a car-audio brand comes with a known volume and tuning frequency. The catch is fit: the cutout, mounting depth and internal volume all have to suit your particular sub. Below are the empty boxes we’d consider, with the numbers you need to check before you order.
The short version
- Best ported single 12: Skar SK1X12V (2.00 cu ft, tuned to 36 Hz).
- Best kerf-port design: CT Sounds CT1X12 (2.13 cu ft gross, 34 Hz).
- Best for trucks and tight trunks: Skar AR1X12V, only 10.25 inches of mounting depth.
- Best dual 12: Skar SK2X12V (4.00 cu ft, 32 Hz).
- Best sealed: QPower HD112, or the Belva 1TRUCK12 for behind a seat.
Check these before you buy
- Cutout diameter: it must be smaller than the sub’s outer flange but at least as big as the sub’s published cutout. For example, the Rockford P3D4-12 needs an 11.25-inch hole, so it drops straight into an 11.34-inch cutout but needs the hole enlarged in an 11.00- or 11.125-inch box.
- Mounting depth: the box’s depth behind the baffle must exceed the sub’s mounting depth.
- Volume: compare the box’s net volume with the range your sub’s maker recommends. Too small chokes the bass; too big risks over-excursion in a ported box.
- Sealed or ported: ported boxes play louder and deeper for the same power; sealed boxes are smaller and tighter. Our sealed vs ported guide explains which suits your music.
Our picks
Skar Audio SK1X12V
For most single 12-inch subs that want a ported box.
- 2.00 cu ft
- Tuned to 36 Hz
- 11.00″ cutout
- 13.75″ mounting depth
Skar publishes the volume, tuning and depth, which is exactly what you need to match a sub. 36 Hz is a good all-round tuning for most music.
- Full specs published
- Deep enough for most 12s
- Sold by Skar Audio
- 11-inch cutout may need enlarging for some subs
CT Sounds CT1X12
For a little more depth and a larger cutout.
- 2.13 cu ft gross
- Tuned to 34 Hz
- 11.34″ cutout
- 13.50″ mounting depth
- 3/4″ MDF, polyfill lined
CT Sounds uses a kerf (curved) port, poly-filled walls, dado and miter joints, and pre-wired 12-gauge leads to the terminal cup. The larger cutout fits more subs without trimming.
- Kerf port and solid joinery
- Bigger cutout fits more subs
- Pre-wired terminal
- Gross volume, so net is a little less
- Large box for small trunks
Skar Audio AR1X12V
For a ported 12 where depth is limited.
- 1.75 cu ft gross
- Tuned to 36 Hz
- 11.125″ cutout
- 10.25″ mounting depth
- Armor-coated finish, kerf port
The bed-liner style finish stands up to cargo, and the shallow mounting depth suits trucks and SUVs. Check that your sub is shallow enough.
- Tough coated finish
- Shallow depth
- Kerf port
- Not deep enough for many standard 12s
- Smaller volume than the SK1X12V
Skar Audio SK2X12V
For a pair of 12s in one ported box.
- 4.00 cu ft
- Tuned to 32 Hz
- 11.125″ cutouts
- 13″ mounting depth
Twice the volume of the single box with a slightly lower tuning, which suits a pair of 12s for deep, loud bass. Pair it with the right amp using our guide to amps for two 12s.
- Full specs published
- Lower tuning for deep bass
- Sold by Skar Audio
- Big and heavy
- Cutouts may need enlarging
QPower HD112
For a single 12 in a compact sealed box.
- Sealed
- 1″ MDF front baffle
- 3/4″ MDF body
Sealed boxes are smaller and more forgiving of volume mismatches. The extra-thick front baffle helps stiffness where the sub mounts.
- Thick baffle
- Compact
- Forgiving to set up
- QPower lists few acoustic specs
- Less output than a ported box
Belva 1TRUCK12
For single-cab trucks and hatchbacks.
- Sealed, angled
- 0.75 cu ft
- 5/8″ MDF, polyfill
An angled sealed box that fits behind a truck seat. 0.75 cu ft is small, so it suits shallow or compact 12s designed for small sealed boxes.
- Fits behind a seat
- Angled shape
- Polyfill included
- Too small for many standard 12s
- Thinner 5/8″ MDF
QPower QBOMB12VL
For a basic vented 12 on a tight budget.
- Vented
- 3/4″ MDF
A low-cost vented option. QPower publishes far fewer details than Skar or CT Sounds, so confirm the volume and tuning suit your sub before buying.
- Low cost
- 3/4″ MDF
- Few published specs
Side-by-side
| Box | Type | Volume | Tuning | Cutout | Depth |
|---|---|---|---|---|---|
| Skar SK1X12V | Ported | 2.00 cu ft | 36 Hz | 11.00″ | 13.75″ |
| CT Sounds CT1X12 | Kerf ported | 2.13 cu ft gross | 34 Hz | 11.34″ | 13.50″ |
| Skar AR1X12V | Kerf ported | 1.75 cu ft gross | 36 Hz | 11.125″ | 10.25″ |
| Skar SK2X12V | Ported, dual | 4.00 cu ft | 32 Hz | 11.125″ | 13″ |
| QPower HD112 | Sealed | Not listed | n/a | Not listed | Not listed |
| Belva 1TRUCK12 | Sealed, angled | 0.75 cu ft | n/a | Not listed | Not listed |
What about 10-inch subs?
Several of these makers also sell 10-inch versions; CT Sounds, for example, lists a CT1X10 alongside the CT1X12. The same rules apply: check cutout, depth and volume against your sub’s spec sheet. 10-inch subs need much less volume than 12s and the right amount varies a lot between models, so use your sub’s recommendations or our box designer rather than guessing.
Prefab, loaded or custom?
- Prefab empty box: cheapest and fastest if you already own a sub, but sizes are generic.
- Loaded enclosure: the sub is pre-matched to the box. See our best loaded enclosures.
- Custom box: exact volume and tuning for your sub and car. Our box designer works out the dimensions.
FAQs
Can I put any 12-inch sub in any 12-inch box?
No. Check the cutout, mounting depth and the sub’s recommended volume. A sub designed for a small sealed box can be damaged in a big ported box.
How do I enlarge a cutout?
Use a jigsaw and sand the edge smooth, then seal the gap with the sub’s gasket. Measure twice; you can’t make a hole smaller.
Does carpet matter?
Not acoustically. It protects the box and looks tidy.
Should I add polyfill?
In a sealed box, some polyfill can make the box act slightly larger. In a ported box, keep it away from the port.