Room Acoustics Simulator
Sound in a room is a wave: it spreads from the source, reflects off every wall, interferes with itself and slowly dies as surfaces absorb it. This simulator solves the wave equation on your floor plan with a finite-difference time-domain (FDTD) scheme, the method acousticians use for low-frequency room modelling. Draw walls in concrete, glass, wood, curtain or foam, place a source and a listener, and press Clap to watch the wavefronts in slow motion. The simulation records the impulse response at the listener and reports the reverberation time (RT60), early decay time, clarity and definition, the frequency response with its room modes, and a loudness map of dead spots. Then listen: play a clap, a drum loop, a guitar or your own recording through the room by convolution, and download the impulse response as a WAV for any convolution reverb.
Runs 100% in your browser — simulations are computed locally on your device.
Notes
- The floor plan is simulated in 2D on a grid of a few centimetres; the floor and ceiling are included as a uniform loss (a "2.5D" model). The wave simulation is exact up to the frequency shown in the results, typically 400–900 Hz; above that the reverb tail is synthesized from the simulated energy decay.
- Sabine’s 1898 formula, RT60 = 0.161·V/A, is shown for comparison: it assumes the sound field is perfectly diffuse, which long corridors, focusing ellipses and rooms with all the absorption on one surface violate.
- Walls are "locally reacting" surfaces whose absorption is set by an admittance boundary condition; each material uses a single mid-frequency coefficient, while real materials absorb bass and treble differently.
- C80 compares sound energy in the first 80 ms after the direct sound with everything later (clarity for music); D50 is the share arriving in the first 50 ms (speech intelligibility).
- Runs 100% in your browser — simulations are computed locally on your device.
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