Speaker Box Calculator
Building a speaker enclosure? Enter your internal box dimensions to calculate the gross and net internal volume in cubic feet and liters. The calculator accounts for driver displacement and internal bracing to give you the actual usable volume your speaker driver will see.
Getting the enclosure volume right is critical for speaker performance. Too small and the bass sounds thin and boomy. Too large and the bass becomes loose and undefined. Every speaker driver has a recommended enclosure volume in its spec sheet (Thiele-Small parameters).
Enclosure types:
- Sealed (acoustic suspension): Tight, accurate bass with a gentle roll-off. Easier to build. Requires less volume than ported designs.
- Ported (bass reflex): Louder bass output and deeper extension, but steeper roll-off below tuning frequency. Needs more volume and careful port tuning.
- Bandpass: Driver is fully enclosed between two chambers. Narrow but very loud frequency response. Complex to design correctly.
Always measure internal dimensions (not external). Subtract wall thickness from the outside measurements. For 3/4-inch MDF, subtract 1.5 inches from each dimension (two walls).