Subwoofer enclosure design guide.

Getting started with SubForge for Windows

1. Extract the complete Windows package. Keep the executable, its Data folder and the Unity DLLs together.
2. Start SubForge.exe from the extracted folder.
3. Free opens immediately without signing in. For Basic or Pro, create and verify your account on the website before purchase, then sign in with that account in the app.
4. Use New to start a project, or Open to load a saved JSON project.

The interface is English. Free, Basic and Pro use the same Windows app.

Driver & T/S parameters

Open this section in the left inspector. Filter by Manufacturer and select a Model, or enter your own values. Some catalogue records are incomplete or await verification; compare the data with the manufacturer’s specifications or your measurements.

Open Driver count & wiring to set voice coils, Series or Parallel coil connection, Drivers in series and Parallel branches. Re, Le and BL are entered for all coils in series. Free and Basic support up to two drivers; Pro supports up to eight.

Driver appearance controls the visual model. Appearance does not replace the driver’s T/S data or determine its mounting dimensions.

3D subwoofer box design: sealed, bass reflex and passive radiator

The left inspector stays alongside the model. Its sections are Acoustic Load, Driver & T/S parameters, Driver count & wiring, Cabinet & construction, Ports & Tuning, Amplifier, DSP filters - PRO and Driver appearance.

• Acoustic Load: choose sealed, infinite baffle, bass-reflex or passive radiator. Losses are grouped under Qa / Ql / Qp.
• Cabinet & construction: dimensions, wall thickness, baffles, bracing, materials and edge details. Advanced construction requires Basic or Pro.
• Ports & Tuning: configure round or slot ports and tuning for bass-reflex designs, or passive-radiator parameters for PR designs.
• Perspective, Front, Fit, Cutaway: use these controls above the model. Right-drag to orbit and middle-drag to pan. Use the full-screen icon to enlarge the view.
• Select an edge or brace for contextual editing. Placement checks retain the previous position when a move is invalid.

Related setting edits are grouped before rebuilding. During pending changes, graphs show the previous results until recalculation completes. Click a setting label or Details for contextual help.

Acoustic simulation: SPL, impedance and cone excursion

Select Analyse in the left rail for larger graphs and amplifier/DSP work. The main graphs are SPL RESPONSE, INPUT IMPEDANCE and CONE EXCURSION.

Select a frequency to read ANALYSIS FREQUENCY, SPL, PHASE, IMPEDANCE, CONE, PORT / PR and GROUP DELAY. Port speed or passive-radiator displacement depends on the acoustic load.

Excursion headroom

The indicator compares peak simulated cone displacement across the analysed range with the entered one-way Xmax at the configured drive level. Its status colour is a measurement warning, not a recommendation for cabinet volume. Unknown Xmax produces an unrated result.

Model limits

The linear small-signal model does not predict thermal compression, large-signal behaviour, port turbulence or room/car acoustics. Check driver data and validate a finished design through measurement.

Separate website example

The website demo uses an ideal sealed-box calculation with fixed Fs = 28 Hz and Vas = 80 L: Fc = Fs × √(1 + Vas / Vb) and Qtc = Qts × √(1 + Vas / Vb). It omits losses, DSP and room effects. Its exported JSON is an example configuration, not a desktop project.

Amplifier & DSP

Amplifier provides Source voltage · V RMS (up to the voltage corresponding to 1500 W per woofer at the reference load) and Source resistance · Ω (0–4 Ω). The displayed Power ≈ W RMS is an estimate from DC resistance, wiring and source resistance before DSP. Actual AC power varies with frequency and impedance; this value is not the driver’s power rating.

DSP filters - PRO includes High-pass, Low-pass and Parametric EQ. HP slope and LP slope offer Butterworth roll-offs of 6, 12, 18 or 24 dB/oct. Parametric EQ has frequency, Q and gain controls.

Build checks and conceptual cut lists PRO

Select Build to open ENGINEERING CHECKS and CUT LIST · CONCEPT. Review panel dimensions and geometry warnings. Use Export printable construction report for a report, or Export CSV in the application footer for numerical simulation results.

Projects & recovery

The top bar contains New, Open, Save and Save as. Projects use JSON. Use Undo, Redo and Recover session below the top bar; Ctrl+S saves, Ctrl+Z undoes, and Ctrl+Y or Ctrl+Shift+Z redoes outside text inputs.

Save and export first apply pending settings. Design comparison is available for projects permitted by your edition. A project requiring a higher edition cannot grant access to those features.

Account & Editions

Free works without an account or internet connection. Basic and Pro require sign-in and online licence verification. Open Account for account actions and Editions for the in-app overview.

Basic input validation and excursion warnings remain available in every edition. Paid editions include one year of application updates, and you retain versions released during your paid update period. An optional extra update year costs €29. See Editions for current prices and update terms. Register and verify your account before purchasing Basic or Pro; Free needs no account.

CURRENT WINDOWS RELEASE

SubForge Studio 1.17.0.

The desktop workspace includes the updated startup and account screens, Free slotport designs, expanded driver and port controls, and the current Free / Basic / Pro feature ranking. Amplifier drive is adjustable up to 1500 W per woofer at the reference load. Pro includes selectable DSP slopes and construction exports.

Application images show example designs; some show paid features. Compare all edition features.

Read the 1.17.0 release notes · Download for Windows

Explore the Studio workspace.

SUBFORGE STUDIO

DesignAnalyseBuild

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