Version 1.9.9 · Free
Plan the sub array.
Then rig it
once.
SubSim predicts how a subwoofer array covers an audience — flown or ground-stacked, in a line, end-fire or cardioid, in open air or a room with walls. Type the venue, pick a setup, press Predict, and see where it is loud, where it thins out, and why.
Windows 10 or 11 · no licence · no account · works offline
What it does
The questions you ask at load-in, answered before you get there.
Describe the audience area, choose a cabinet and a formation, and SubSim adds the sound from every box — with its delay, polarity and directivity — so cancellation and coverage show up the way they do on site.
- 1Describe the venue
Audience width and distances, ear height, temperature, floor type. Optionally a room with walls.
- 2Choose the array
Start from a sample, or pick a cabinet, flown or ground, formation and quantities.
- 3Predict
One button. Maps, coverage spread and level numbers update from the same calculation.
- 4Adjust and save
Change any cabinet's level, delay or polarity, then save the session as a file.
Functions
Real screens from the program.
Every picture below is a screenshot of SubSim 1.9.9. Nothing here is a mock-up.
Sample configurations
Nine ready-made setups in a drop-down — lines, cardioid stacks, end-fire arrays, left and right clusters. One click loads and predicts. Everything stays editable.
- Dual 18 inch front-loaded boxes to start
- Change quantity, spacing, delay or polarity afterwards
- Flown or ground stack, columns and rows
- Simple view for a first run, Full view for every control
Plan view — drag the array
Top-down at ear height, with the audience outlined. Hover for the level at any point. Drag the array anywhere across the venue, with or without snap to 1 m.
- End-fire: rear row delayed so rows add forward and cancel behind
- Put the array inside the audience area if that's the job
Side view — whole slice or just the audience
The side view shows the full vertical slice through the array. Switch it to Audience and it colours only the strip at ear height and leaves the rest dark, so you read what people hear, not the loud air above the stack.
Room and walls — reflections and standing waves
Turn on walls with a material and thickness on each side. Standing waves need two facing walls: with walls on both sides of the audience, or in front of and behind the subs, the sound rings at low frequencies and the bands you see here are those standing waves. A single wall gives reflections but no ringing, and with no walls at all there are none.
- One line per wall: distance, thickness, material
- Room size in X, Y and Z
- Open at the front: no wall there, so no ringing along the depth
- A reflecting wall inside the audience: set its distance there
Time alignment
Add delay subwoofers partway down the venue, type the distance, and SubSim derives the delay. Then see when each system arrives at a listener, the phase between them, and whether they add or cancel.
Height advisor for flown arrays
The floor bounce makes a null. Raise the array too far and that null lands inside your passband. The advisor sweeps the hang height and shows the ripple and the front-to-back spread, with the best height marked.
Loudspeaker catalogue
Choose from a catalogue of subwoofer models from many manufacturers to set cabinet size and level, or attach a cabinet's own balloon data. The catalogue lists models; it does not replace the maker's measured data, and the program says so.
Sample configurations
Start from a setup that already works.
Choose one on the Cabinets page. It loads dual 18 inch front-loaded boxes and predicts at once.
| # | Sample | What you get |
|---|---|---|
| 1 | Center line, 4 boxes | One line side by side, all in phase |
| 2 | Center line, 8 boxes | One line of 8 |
| 3 | Left + right line, 4 each | A line each side, 20 m apart |
| 4 | Center cardioid, 4 boxes | Front boxes plus an inverted, delayed, rear-facing box |
| 5 | Center cardioid, 8 boxes | 6 front and 2 rear-facing |
| 6 | Left + right cardioid, 4 each | A cardioid stack each side, 20 m apart |
| 7 | Center end-fire, 4 columns × 2 rows | Rear row delayed: adds forward, thins out behind |
| 8 | Center end-fire, 8 columns × 2 rows | 16 cabinets |
| 9 | Left + right end-fire cardioid pairs | Front row plus an inverted, delayed rear row on each side |
The physics
Plain about how it works.
Every cabinet is a point source. SubSim adds their sound as complex pressure — magnitude and phase — at every point, which is why the cancellations you meet in real arrays show up.
Coherent sum
Each cabinet's pressure, with delay, polarity and directivity, is added as a phasor. Levels across a band are then summed by power.
Floor and walls
The floor and each wall become mirror-image sources, and a wall's reflection depends on its material and thickness. Parallel walls ring at n × c / 2L.
Air and temperature
Speed of sound from temperature, and air absorption to ISO 9613-1 with humidity. Temperature changes distances, never delays.
Checked against closed forms
Automated tests compare the engine with hand-worked results: inverse-square law, coherent doubling, the array-factor formula, floor-null frequency, the wall-notch frequency.
ISO 9613-2 readout
The standard's ground effect is shown beside the floor-bounce result at the listener marker. It is a level correction with no phase, so the maps use the floor-bounce model.
Ground presets
Concrete, wooden deck, packed earth, grass and snow set the floor reflection, each labelled with its ISO 9613-2 ground class.
Download
Free. No licence, no key, no timer.
Install it, use it, share it with your crew.
Free
SubSim 1.9.9 for Windows
No cost, ever asked
Installs for your user — no administrator needed. Works offline. Sessions are files you choose.
Download SubSim-Setup-1.9.9.exeWindows 10 or 11, 64-bit. Windows may show a SmartScreen notice because the installer is not code-signed yet: choose “More info”, then “Run anyway”.
What you get
- Flown and ground-stack arrays
- Line, end-fire and cardioid formations
- Left and right clusters, delay subs
- Rooms with walls, standing waves
- Time alignment and height advisor
- Save and open sessions
FAQ
Quick answers.
Is it really free?
Yes. No licence, no activation, no expiry. SubSim is offered free by Master Pro Sounds and Lights Services.
Who makes it?
SubSim is owned and developed by Master Pro Sounds and Lights Services, Cebu, Philippines.
Does it need the internet?
No. It runs entirely on your computer and keeps your sessions in files you choose.
Can I use my manufacturer's data?
You can attach a cabinet's balloon data (as a CSV) to the array or to a single cabinet. Without it, SubSim uses a generic first-order pattern and tells you so.
How does it calculate?
It adds the sound from every cabinet as complex pressure, magnitude and phase, with mirror-image sources for the floor and walls, air absorption to ISO 9613-1 and the standard’s ground effect alongside. The engine is tested against closed-form acoustics results. As with any prediction software, confirm the final design on site with a measurement microphone.
What about Mac or Linux?
SubSim is Windows-only for now.