Box Builder

📋 Set trunk limits → 🔊 Choose driver → 🎯 Target volume → ✨ Get dimensions

Mobile tip: use the main setup cards first, then open Advanced only if you need port routing or 3D tuning controls.

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Overview

What Box Builder Helps You Do

Box Builder is a practical enclosure-planning tool for people who want cleaner first-pass numbers before they start cutting wood.

Use Case 01

Size A Box Around Real Space Limits

Set trunk or hatch constraints first, then work backward into box dimensions that are actually buildable inside the vehicle.

Use Case 02

Compare Sealed And Ported Options

Adjust driver displacement, wood thickness, bracing, and port dimensions to understand how much usable airspace is left.

Use Case 03

Check Fit Before You Build

Use the live dimensions, warnings, 2D views, and 3D preview as a planning pass before material, labor, and install time are committed.

Support

How To Use This Site Responsibly

Every number on this site should be treated as a planning aid, not as a replacement for final build judgment. Material thickness, panel layout, port routing, driver tolerances, and vehicle trim can all change the finished result.

If you want more context before using the calculator, visit the guides, read the about page, or use the contact page to report issues or suggest improvements.

Maximum Trunk / Hatch Area

These are the hard limits for your enclosure based on available space.

Use trunk constraints

Suggestion Mode

Max Width (in) Max Height (in) Max Depth (in)

Available space: calculating...

Driver Selection

Driver Size (in)

Driver Displacement (ft³) — Reduces usable volume Driver Depth (in) Driver Quantity

Driver Cutout Diameter (in) Mounting Depth (in)

Sensitivity (dB @ 1W/1m) Voice Coil Diameter (in)

Paste driver recommended volumes (Parts Express)

Parsed Sealed Volume (ft³) Parsed Vented Volume (ft³) Sealed F3 (Hz) Vented F3 (Hz)

You can adjust these values manually — edited fields are highlighted. Click Apply Preview to use the previewed values. Clicking Parse & Apply will re-parse the paste and reset these preview values to the pasted data.

Enclosure & Advanced Port Setup Sealed cabinet

Enclosure Type Target Tuning Frequency (Hz) Wood Thickness (in) Bracing Displacement (ft³)

Gross uses internal airspace. Net subtracts driver, bracing, and internal port displacement.

Port Type Slot Port Width (in) Slot Port Height (in) Slot Port Length (in) Slot Port Count Round Port Diameter (in) Round Port Length (in) Round Port Quantity

Auto Port Mode Auto Port Area (in² / ft³) Min Round Port Diameter (in) Slot Aspect Ratio (W:H) Min Slot Height (in) Min Port Length (in)

Speed Of Sound (in/s) Inside End Correction Outside End Correction Length Adjustment (in)

Manual port sizing is active.

Port mode: manual sizing keeps your typed values. Auto Length updates length only. Full Auto can change opening size and length.

Auto Dimension Priority 1 Auto Dimension Priority 2 Auto Dimension Priority 3

Width Weight (%) Height Weight (%) Depth Weight (%)

Auto dimensioning uses the priority order first, then weights to bias the base shape before fitting target volume within constraints.

Tuning frequency affects port design. Sealed enclosures don't require tuning calculation.

Port Mount Face Multi-Port Layout Port Spacing (in) Port Extension Mode

Port Offset X (in) Port Offset Y (in) Port Offset Z (in)

Slot Port Internal Channels Slot Channel Gap (in) Slot Fold Axis Slot Fold Direction Slot Lead Run Offset (in)

Offsets are measured from the enclosure center. The selected face uses the two relevant axes and ignores depth-normal offset.

3D Shell Opacity 3D Port Opacity Port Wall Thickness (in)

Calculated Output

External • Rectangular • Sealed Fit status pending Manual sizing

Internal Dimensions -

External Dimensions -

Gross Internal Volume -

Net Before Driver/Bracing -

            Net After All Displacement
            -
          

Gross is internal airspace before displacement. Net values reflect the current enclosure setup.

Status

Review pending

Use this as a build-sanity panel. Informational notes are normal, but fix warnings before trusting the cut sheet.

Live Box Diagram

W (in) H (in) D (in)

Quick adjust uses your current dimension mode (internal/external). -

Designer Mode (drag box handles in diagram)

Designer Snap (in)

Manual Box Calculator

Manually enter your box specs and get the usable volume right here without jumping down to the main output cards.

Cabinet Shape Width (in) Height (in) Depth (in) Wood Thickness (in)

External Internal

External mode treats width, height, and depth as outer dimensions. Internal airspace is calculated after subtracting wall thickness.

Enclosure Type Port Type Driver Cutout Diameter (in) Driver Displacement (ft³) Driver Quantity Bracing Displacement (ft³)

Slot Port Width (in) Slot Port Height (in) Slot Port Length (in) Round Port Diameter (in) Round Port Length (in) Round Port Quantity

Internal Dimensions -

Gross Internal Volume -

Port Displacement -

Total Displacement -

              Net Volume
              -
            

Sealed boxes subtract driver and bracing displacement. Ported boxes also subtract the internal port volume.

Quick Volume Sizing

Get suggested box dimensions for a target volume.

Suggestion Mode

Auto Dimension Priority 1 Auto Dimension Priority 2 Auto Dimension Priority 3

Width Weight (%) Height Weight (%) Depth Weight (%)

Desired Net Volume (ft³)

Suggested Internal Dimensions -

3D Preview

Use 3D to check fit, orientation, and port routing after your main sizing is close. The primary workflow is still the sizing cards and 2D views.

On phones, use 3D mainly as a viewer. The most reliable editing tools are still the main 2D designer surfaces.

3D Review Controls Viewer mode

Most users only need view presets, fit status, and interior on/off. Lock view and zoom only if you want to edit directly in 3D.

Depth Direction Box Position (Depth) Sub Facing Driver Layout Show Interior Lock 3D Zoom Lock 3D View Allow 3D drag editing

3D fit status: -

3D interaction hint: -

3D debug: waiting for pointer input.

2D Layout Views

Precise Layout Tools Front • Side • Top

Use these flat views when you need accurate placement and folded-slot review. They stay synchronized with the live diagram and 3D preview.

Front

Side

Top

Cut Sheet

Build view keeps construction details separate from sizing workflow.

Guides

Learn Before You Build

These pages are meant to help first-time builders understand the tradeoffs behind the numbers the calculator gives them.

Guide 01