Design the box before you cut the wood.
BassDesign turns your subwoofer's datasheet into a box that works: live response graphs, port size and air speed, cabin gain for your car, then a 3D build plan and cut list. In your browser, free, with nothing locked.
- No account
- Dimensions and cut list free
- Desktop, tablet and phone
Fs 30 Hz · Qts 0.42 · Vas 50 L. Small-signal response with no subsonic filter, so F3 reads a little lower than in the calculator, which adds the filter, losses, power, cone travel, port speed and the cabin.
- Sealed
- Ported
- 4th-order bandpass
- 6th-order bandpass
- Passive radiator
- Free air
Everything you need to build it, not only the volume.
Most calculators stop at a number of litres. BassDesign follows the box all the way to the saw.
Every graph that matters
Response, maximum output limited by cone travel and power, impedance, phase and group delay, all redrawn as you drag.
Tuned for the car it goes in
Pick a vehicle size and see how the cabin lifts the low end, so you choose the tuning for the car and not for an empty room.
Ports that stay quiet
Port length with proper end correction, air speed at full power with safe zones, and the pipe resonance to keep out of your crossover.
Real outside dimensions
Driver, port and bracing displacement added automatically. Set panel thickness and fit the box to a width or height.
See it, then cut it
Rotate the box in 3D, look through it in x-ray, explode the panels, then take the cut list to the workshop.
Compare and share
Pin up to six designs and overlay them on every graph. Send any design as a link; nothing to install, nothing to sign.
From datasheet to cut list in three steps.
Enter your driver
Type Fs, Qts and Vas from the datasheet, or paste the spec block. BassDesign fills in the rest and flags numbers that do not add up.
Shape the box
Pick an enclosure, start from a classic alignment or the optimizer, then adjust volume and tuning while every graph updates.
Build it
Get outside dimensions, the port layout, a 3D view and a cut list for your panel thickness.
Free. All of it.
You should not have to pay to find out how big your box is. Every result BassDesign calculates is yours to see and use.
- Dimensions and cut list included. No unlock after you have entered everything.
- No account. Your designs are saved in your browser.
- Share by link. Send a build to a friend or a forum thread.
- Works on your phone. A real layout for small screens, not a squeezed desktop.
Need one number fast?
Single-purpose calculators for the most common questions. Each one opens in the full calculator when you want more.
Sealed box calculator
Box volume for a target Qtc, with F3 and the response curve.
Open →Quick toolPorted box calculator
Classic (Keele) starting point, tuning, port length and F3 from three datasheet numbers.
Open →Quick toolPort length calculator
Round or slot ports with proper end correction, port volume and pipe resonance.
Open →Learn the why behind the numbers.
Sealed vs ported subwoofer box: which one should you build?
How to calculate subwoofer box volume (net vs gross)
How to calculate subwoofer port length
What tuning frequency should your subwoofer box have?
Subwoofer port noise: how big should a subwoofer port be?
Thiele/Small parameters explained: what each number means for your box
Questions builders ask
Is BassDesign really free?
Yes. Every feature, including box dimensions, the cut list and the 3D build view, is free to use with no account and no trial. There is no paywall in front of your results.
What enclosure types can I design?
Sealed, ported (vented) with round or slot ports, 4th-order and 6th-order bandpass, passive radiator and free air (infinite baffle).
How accurate are the results?
BassDesign models the driver electrically, mechanically and acoustically from its Thiele/Small parameters, including box losses and port end correction. The engine is tested against classic closed-form results. Real results still depend on correct driver data and how the box is built.
Does it account for car cabin gain?
Yes. Turn on cabin gain and pick a vehicle size to see how the car will lift the low end, which changes the best box size and tuning for in-car use.
Do I need to install anything or sign up?
No. It runs in any modern browser on desktop, tablet or phone. Your work is saved in your browser and you can share a design with a link.
Can I use metric and imperial units?
Yes. Switch between centimetres and litres or inches and cubic feet at any time; the design stays the same.