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Wedge Subwoofer Box Calculator
Enter the outside width, height and both depths of a wedge box and get its internal and net volume, the taper and the rake angle. Or give it the volume your driver wants and it solves the width you need to cut.
Wedge Box Calculator
Outside dimensions in, volume out. Or lock the height and depths and solve the width for a target net volume.
Volume, taper and rake
Side profile, to scale
What the same box does at other heights : rake held, floor depth held
| Height | Top depth | Taper | Internal ft³ | Net ft³ |
|---|---|---|---|---|
| Calculate to see the sweep. | ||||
Volumes are internal air volume less the displacement you enter. Bracing and port volume are not deducted here; on our ported wedges the listing states the net figure after the port.
Why a Wedge Box Has Two Depths
A wedge enclosure keeps its front baffle vertical and rakes the rear panel, so the cabinet is deep at the floor and shallow at the top. That is what lets it sit flush against a leaning seat back and recover the floor space a square box wastes. It also means one depth figure tells you nothing: you need the depth at the floor and the depth at the top, and the difference between them is the taper.
On every Proline X wedge the rake is a constant 20 degrees, so the taper is simply the cabinet height times the tangent of 20 degrees. A 13 inch tall ten tapers about 4.7 inches; a 15 inch tall twelve about 5.5; an 18 inch tall fifteen about 6.6. The calculator reports the rake your dimensions imply, so you can see at a glance whether a listing is a true wedge or a box that only tapers a little.
If you are measuring a vehicle rather than a box, start with how to measure for a wedge box behind a truck seat. If you are trying to work out whether a listing is a wedge or an angled-baffle box, this explains which panel is tapered on each.
The Math, in One Line
The side of a wedge is a trapezoid, so its area is the height times the average of the two depths. Multiply by the internal width for cubic inches and divide by 1,728 for cubic feet. The internal figures are the external ones less the walls: two wall thicknesses off the width and the height, one off the floor depth and one off the top depth for the back panel, plus the front baffle stack.
Our Performance Optimized wedges are built with the side panels dropped into dados inset half an inch from each shell edge and a four-layer front (trim, second baffle, shell front, back). That is why the Proline X preset takes 2.5 inches off the width and 3.0 off each depth rather than 1.5. It reproduces the published net volumes on our sealed wedges to within a few hundredths, which is a useful check on any wedge listing: if the volume does not fall out of the dimensions, one of the two numbers is wrong.
For the volume a driver actually wants, use the sealed box calculator for a Qtc target, or the airspace calculator for a manufacturer-style recommendation. A ported wedge needs more; where the port goes on a ported wedge covers what the port costs in depth, and the port area calculator sizes the slot.
Real Builds, Checked Against Their Listings
Four Proline X wedges from the catalogue, run through this calculator with the Proline X preset.
| Build | W × H (in) | Depth floor / top (in) | Listed net | Calculator |
|---|---|---|---|---|
| Alpine S2-W10 sealed | 19.26 × 13 | 11.10 / 6.37 | 0.58 ft³ | – |
| JL Audio 12W3v3 sealed | 23.75 × 14.5 | 13.50 / 8.25 | 1.25 ft³ | – |
| JL Audio 12W3v3 dual sealed | 32.00 × 16 | 16.86 / 11.04 | 1.25 per chamber | – |
| Image Dynamics IDMAX12 ported | 29.00 × 15 | 16.46 / 11.00 | 1.71 ft³ after the port | – |
The dual is quoted per chamber, so the calculator’s whole-box figure is compared at half. The ported box is quoted after the port’s own volume, so the calculator’s figure runs higher; the difference is the port channel and the braces.
Every one of these is in the wedge subwoofer box collection, sealed and ported, cut to the driver you own.
Wedge Box Calculator FAQ
How do you calculate the volume of a wedge subwoofer box?
Why does a wedge box have two depths?
Is the taper on the front or the back of the box?
What wall thickness should I enter?
What net volume does my subwoofer want?
Does the wedge shape change the sound?
Want the box cut for your driver?
Send us the driver and the space and we will tell you whether a wedge fits before you order. Call 931-563-5151 or use the contact page.
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