Subwoofer Finder

For a slot port, area = width × height. For a round port, area = π × diameter² ÷ 4.

The tool sizes the port for the target velocity and calculates the required effective port length. You can model straight, folded, or custom-shaped ports in Shapr3D as long as the total effective length and cross-sectional area are maintained.

Enter clear internal dimensions. The builder subtracts the selected woofer displacement, calculated port displacement, and any extra displacement you enter for bracing or other internal parts. Use Build Me a Box below when you want the tool to solve dimensions for you.

Worst-case peak flow estimate if the cone reaches Xmax at the tuning frequency. Use this as a conservative sizing check — it is not a prediction of actual operating port velocity.