Free builder tools
Subwoofer Enclosure Calculator
Work out box volume, port length and EBP before you cut a single panel. Enter your numbers in inches and hit Calculate.
Quick guide: sealed or ported?
Not sure which box to build? Start here.
Tight, accurate bass
Smaller box, punchy and musical. Great for rock, metal and anyone short on trunk space. Easier to build: no port to tune.
Louder, deeper bass
Bigger box with a tuned port that adds output around the tuning frequency. The pick for hip-hop, EDM and SPL builds.
What the number means
EBP = Fs ÷ Qes. 50 or under suits a sealed box, 50 to 90 works in either, and 90 or more is made for ported.
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Enclosure calculator FAQ
What is the difference between gross and net volume?
Gross volume is the empty space inside the box. Net volume is what the subwoofer actually “sees” after you subtract the speaker, the port and any bracing. Always match the net volume to your subwoofer’s recommended box size.
Should I enter inside or outside dimensions?
Enter the outside dimensions and set the wood thickness (0.75 in for standard MDF). The calculator removes the walls for you. If you measured the inside, set the wood thickness to 0.
How much does bracing matter?
Braces stop panels from flexing, but they take up air space. Use the Brace Volume Subtractor to see how much volume they remove so you can make the box slightly bigger to compensate.
What port size and tuning should I use?
Most daily builds are tuned between 30 and 38 Hz. Lower tuning gives deeper bass, higher tuning hits harder. Aim for roughly 12 to 16 square inches of port area per cubic foot of net volume to keep port noise down.
Where do I find Fs, Qes and speaker displacement?
They are in your subwoofer’s spec sheet or manual, usually under “T/S parameters”. Most of our product pages list them in Product Details & Specs.
