American Bass Audio
Box & Port Calculator
Calculate enclosure volume and port length for your subwoofer build
Enter Dimensions: You know your box size or have space constraints. Enter width, height, and depth to calculate volume and port length.
Net Volume
0.00ft³
After all displacement
Port Length
0.0in
For 32 Hz tuning
Port Area: Good
Velocity: Quiet
Fit: Port fits inside box
Enclosure Dimensions
External measurements
Width (External)
Measure the outside left-to-right span of your box. This is typically the longest dimension.Trunk tip: Measure your trunk or cargo area first — leave at least 1" clearance on each side.
in
Height (External)
Vertical measurement bottom-to-top.Rule of thumb: 12" subs need at least 13" of height; 15" subs need at least 16".
in
Depth (External)
Front-to-back measurement.Critical: Sub's mounting depth + 1–2" rear clearance must fit inside this (minus 2× wood thickness).
in
Material Thickness
3/4" (0.75") MDF is the industry standard. Use 1" for boxes over 4 ft³ or high-power SPL builds.Avoid: Particle board, plywood under 3/4", OSB.
in
💪 Bracing Recommended
For enclosures over 3 ft³, add internal bracing to prevent panel flex. Use 2-3 braces made from the same material. Adds approximately 0.02-0.05 ft³ of displacement.
Target Volume Mode
Enter your desired net volume, get suggested dimensions
ft³
in
in
💡 Suggested Dimensions
32" × 14" × 16"
Subwoofer
Select size or enter custom displacement
Subwoofer Size
Selecting a size auto-fills a typical displacement for that cone. These are averages — your actual sub may differ. For best accuracy, choose "Custom" and enter the exact Vd from your sub's spec sheet.
Driver Displacement (Vd)
Physical volume your sub's motor/magnet/cone occupies inside the box. Subtracted from gross volume to give net volume. Check spec sheet for "Vd" or "driver displacement."
ft³
1
Enclosure Type
Choose sealed or ported design
🔒 Sealed
Tight, accurate bass
🔊 Ported
Louder, deeper bass
💡 Sealed Box Tips
Sealed enclosures provide tight, accurate bass with excellent transient response. Consider adding polyfill (1-1.5 lbs per ft³) to make the box acoustically larger and smooth the response. Sealed boxes are more forgiving of volume variations than ported designs.
Daily
35 Hz
Balanced
32 Hz
SPL / Low
28 Hz
Slot Port vs. Round Port
Slot: Rectangular channel built from wood. More area per inch of width, handles high power, most competition builds.Round / Aero: Pre-made circular tube. Simpler install. Best for smaller or simpler builds.
Tuning Frequency (Fb)
Resonant frequency of your port — the note where it produces most output.Higher (33–40 Hz): Punchy, rock/country.
Lower (26–32 Hz): Deep, hip-hop/EDM/SPL.
Hz
Slot Port Width
Narrow dimension of your rectangular port.Guide:
2–2.5" — 8–10" subs low power
3–3.5" — most 12" builds
4"+ — 15"/18" or high power
in
Slot Port Height
Tall dimension of port. Usually matches box's internal height.Calculation: External height − 2× wood thickness. Example: 14" box with 3/4" MDF → 12.5" internal.
in
1
Port Velocity: Quiet
No port noise expected at typical output
Calculation Results
All measurements for your build
Gross Volume
0.00ft³
Sub Displacement
0.00ft³
Port Displacement
0.00ft³
Port Area
0.0sq in
📋 Build Sheet
Enclosure TypePorted
External Dimensions32" × 14" × 16"
Internal Dimensions30.5" × 12.5" × 14.5"
Net Volume0.00 ft³
Tuning Frequency32 Hz
Port Dimensions3" × 12"
Port Length0.0"
✂️ Cut List
All pieces needed to build your enclosure
Enclosure Panels
Port Pieces
AMERICAN BASS AUDIO
Subwoofer Enclosure Build Sheet
Enclosure Specifications
Enclosure Type:
External Dimensions:
Internal Dimensions:
Wood Thickness:
Gross Volume:
Net Volume:
Subwoofers:
Port Specifications
Tuning Frequency:
Port Type:
Port Dimensions:
Port Length:
Port Area:
Number of Ports:
Cut List
Disclaimer: This calculator provides estimates for educational purposes only. Always verify calculations independently before building. American Bass Audio is not responsible for enclosures built using these calculations. Measure twice, cut once.