Subwoofer box calculator
Sealed and ported enclosure size, tuning, port length, predicted bass response and the wood cut list — from your driver's Thiele–Small parameters.
Your driver
These numbers are on the driver's box or spec sheet. Vas in ft³ × 28.3 = litres.
Box shape
Quick guide for a 12″ subwoofer: sealed about 28–42 L, ported about 42–71 L tuned 30–38 Hz.
Typical subwoofer box sizes (when you don't know the parameters)
| Size | Sealed | Ported | Usual tuning |
|---|---|---|---|
| 8″ | 8–17 L (0.3–0.6 ft³) | 17–28 L (0.6–1.0 ft³) | 35–42 Hz |
| 10″ | 17–28 L (0.6–1.0 ft³) | 28–42 L (1.0–1.5 ft³) | 32–40 Hz |
| 12″ | 28–42 L (1.0–1.5 ft³) | 42–71 L (1.5–2.5 ft³) | 30–38 Hz |
| 15″ | 42–71 L (1.5–2.5 ft³) | 71–113 L (2.5–4.0 ft³) | 28–35 Hz |
| 18″ | 71–113 L (2.5–4.0 ft³) | 113–170 L (4.0–6.0 ft³) | 25–32 Hz |
A general guide for car subwoofers — every driver is different. The maker's recommended box, or the calculation above from its parameters, is more accurate.