Subwoofer box guides
Short, practical answers to the questions people ask before they build a sub box. Each guide links to the free calculator, which does the math for your exact driver.
- What size box for a 8 inch subwoofer?How big a box does a 8 inch sub need? Typical sealed and ported volumes in cubic feet and liters, port tuning, box depth and dual 8″ sizes.
- What size box for a 10 inch subwoofer?How big a box does a 10 inch sub need? Typical sealed and ported volumes in cubic feet and liters, port tuning, box depth and dual 10″ sizes.
- What size box for a 12 inch subwoofer?How big a box does a 12 inch sub need? Typical sealed and ported volumes in cubic feet and liters, port tuning, box depth and dual 12″ sizes.
- What size box for a 15 inch subwoofer?How big a box does a 15 inch sub need? Typical sealed and ported volumes in cubic feet and liters, port tuning, box depth and dual 15″ sizes.
- What size box for a 18 inch subwoofer?How big a box does a 18 inch sub need? Typical sealed and ported volumes in cubic feet and liters, port tuning, box depth and dual 18″ sizes.
- Sealed vs ported subwoofer box: which is better?Sealed or ported: which hits harder, which sounds better, how much bigger a ported box is, and how to choose for your sub and your car.
- How to calculate a ported sub box and port lengthPort length formula with a worked example, how to size port area, slot vs round ports, port air speed and the mistakes that make a ported box sound wrong.
- Net vs gross subwoofer box volumeHow to calculate a sub box’s volume in cubic feet, the difference between gross and net (airspace) volume, and what to subtract for wood, sub and port.
- Subwoofer box too small or too big: what happens?Is a bigger sub box better? What a box that is too small or too large does to bass, power handling and excursion, and how deep a subwoofer box should be.
- Under-seat and truck subwoofer boxesHow to design a sub box that fits under a truck seat, behind a seat or under a front seat: measuring, angled boxes, shallow subs, sealed vs ported.
- How to build a subwoofer box: plans, cut sheet and tipsBuild a sub box step by step: materials and thickness, cut sheet and plans, gluing and sealing, bracing, terminal and port, and checking the result.
- An online WinISD alternative for car subwoofer boxesModel a subwoofer box like WinISD, in any browser on Windows, Mac or phone, with car cabin gain, a database of about 2,000 subs, plans and a cut sheet.