Speaker Box Volume Calculator

Determine the ideal box volume for sealed or ported speaker enclosures. Optimize your speaker performance with proper volume for bass response and efficiency.

Enclosure Type:

Vas (liters):

Qts:

Target Qtc (sealed only):

Calculated Box Volume

Volume: -- liters

Volume: -- cubic feet

How This Calculator Works

Uses Thiele/Small loudspeaker parameters
Sealed boxes use Qtc alignment (default 0.707)
Ported boxes use Butterworth approximation
Internal volume excludes wood thickness & bracing

Formulas & Notes

Sealed Box Volume: Vb_box = Vb × 1.0–1.5 (depends on desired Q)
Ported Box Volume: Vb_box = Vb × 1.0–1.25 (adjusted for tuning frequency)
Adjust box volume to balance low-frequency extension vs. transient response.
Ported boxes require correct tuning frequency and port size for desired bass performance.

How to Use

Enter the Thiele-Small Vb value (manufacturer spec for your driver).
Select the enclosure type: Sealed or Ported.
If ported, enter the desired tuning frequency and number of ports.
The tool calculates the optimal box volume in liters or cubic feet.
Use the results to design or build your speaker enclosure.

Who Can Use

DIY speaker builders optimizing bass response.
Audio engineers and acousticians designing subwoofers.
Home theater enthusiasts tuning speaker enclosures.
PA system designers selecting proper box volume for low-frequency performance.

Where to Use

Home theater or living room speaker setups.
Professional recording and mixing studios.
PA systems, clubs, and performance venues.
Custom subwoofer and full-range speaker enclosures.

FAQs

Vb is the speaker’s recommended box volume for optimal performance based on its parameters (from manufacturer specs).

Sealed boxes typically require slightly larger volumes than ported boxes. Ported boxes allow tuning via the port but need accurate calculations for optimal performance.

This tool works for speakers with known Thiele-Small parameters. Unknown parameters may lead to inaccurate results.

Speaker Tools