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Subwoofers
Subwoofer Box
Volume Calculator
What this calculator is for
You've sketched out a box on paper and you want to know if the inside will actually be the right size for your subwoofer. Enter your planned external dimensions and the calculator works out the net internal volume after accounting for the wood thickness and anything else taking up space inside — driver, port, and bracing. It then tells you whether that volume is in the right range for your sub.
The volume ranges used here are general guidelines. Always check your subwoofer's spec sheet for the manufacturer's recommended enclosure volume and use that as your primary target. This tool is a useful starting point, not a substitute for your specific driver's specs.
1
Choose your box type
Sealed and ported boxes have different recommended volume ranges, so pick your type first.
Sealed
Tight, accurate bass. More forgiving of volume variations. Best for most music types.
Ported (Vented)
More output at a tuned frequency. Louder but less flexible. Great for hip-hop and EDM.
2
Your subwoofer size
Select your driver size so the calculator knows what volume to aim for. If your sub's spec sheet lists a specific recommended volume, enter that too — it will override the general range for a more accurate verdict.
Driver size inches
Spec sheet volume cu ft optional
| Driver size | Sealed (cu ft) | Ported (cu ft) |
|---|---|---|
| 8" | 0.3 – 0.5 | 0.5 – 0.75 |
| 10" | 0.5 – 0.75 | 0.75 – 1.25 |
| 12" | 0.75 – 1.25 | 1.25 – 2.0 |
| 15" | 1.5 – 2.5 | 2.5 – 4.0 |
| 18" | 3.0 – 5.0 | 4.0 – 6.0 |
3
Your planned box dimensions
Enter the outside dimensions of the box you plan to build, and the thickness of the material you're using. 3/4" MDF is the most common choice for subwoofer enclosures.
W Width — left to right
H Height — top to bottom
D Depth — front to back
All external measurements
Width inches
Height inches
Depth inches
Material thickness
4
Internal displacements
All optional — enter 0 if unsure
Anything inside the box takes up space and reduces the net volume. If you're not sure about a value, leave it at 0 — the calculator will still give you a useful result, just slightly optimistic.
Driver displacement optional
The sub's basket and motor extend into the box. Typical values: 8" ≈ 0.04 ft³ · 10" ≈ 0.07 ft³ · 12" ≈ 0.10 ft³ · 15" ≈ 0.16 ft³. Check your sub's spec sheet for an exact figure — or leave at 0 if you don't have it.
Displacement per driver cu ft
Number of drivers
Bracing displacement optional
Internal braces stiffen the panels but reduce volume. Leave at 0 if you have no internal bracing planned.
Total bracing displacement cu ft
Net internal volume
—
cubic feet
—
cubic inches
—
liters
Calculation breakdown
Gross internal volume—
Driver displacement—
Port displacement—
Bracing displacement—
Net internal volume—
Next Steps
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