Room Acoustics Simulation
The Room Acoustics Simulator uses particle tracing across octave bands to model how sound travels, reflects, and decays inside a room. When the simulation completes, it outputs standard ISO 3382 metrics: reverberation time (RT30), early decay time (EDT), clarity (C50/C80), and more — shown as charts per octave band.
Before you run
You must assign acoustic materials to room surfaces first. The simulation uses absorption and diffusion coefficients from those materials directly in the calculation. See the Acoustic Material Assignment guide.
Also, use Section Planes instead of hiding geometry to expose interior surfaces. Hidden faces are excluded from the simulation.
How to run
- Click the Room Acoustics Simulator button in the SketchAcoustics toolbar
- Click to place one or more sound sources (emitters) inside the room, then press Enter to confirm
- Click to place one or more receivers (listeners) inside the room, then press Enter to start the simulation
- Once complete, results appear as charts per octave band
Results
| Metric | What it measures |
|---|---|
| RT30 | Time for sound to decay 30 dB (extrapolated to 60 dB) |
| EDT | Early decay time — perceived reverb based on the first 10 dB of decay |
| C50 | Clarity for speech — ratio of early to late energy |
| C80 | Clarity for music — wider early window than C50 |
Sound Billiard visualisation
After running the simulation, you can launch the Sound Billiard — an animated ray visualisation showing particle paths through the room. This helps you understand how sound propagates and identify problematic reflection patterns.
Tips
- Place emitters and receivers realistically — where a speaker and listener would actually be positioned in the room
- More particles = more accurate results but longer compute time
- Run the simulation again after adjusting materials to compare how treatment changes affect the metrics