Sound Waves Between Two Walls
Software platform: Excel (OpenOffice and LibreOffice not supported)
As the title says, this software simulates the sound field of a point source placed between two parallel walls.
- Frequency response graph with adjustable time-window and octave smoothing.
- Cumulative spectral decay plot (waterfall plot).
- Impulse response graph.
The simulation is based on the image source model (ISM). The calculation is done up to the 8th reflection from each wall with 1/12 octave resolution.
It is possible to study the following effects with this tool:
- Standing waves between two parallel walls.
- Both steady state and transient effects can be studied.
- The effect of speaker and microphone placement (listening position) on the first reflections (use time-windowed response (<10 msec) to see the comb filtering).
- The effect of speaker and microphone placement (listening position) on the late reflections (standing wave patterns, decay of resonances in the cumulative spectral decay graph).
- The effect of the wall's absorption coefficient on the late and early reflections. E.g. late reflections are more sensitive to the value of the absorption coefficient, because the sound wave strikes the wall more times.
- Not only the decay spectrum of a system can be visualized, but the opposite - how the sound pressure builds up. For this, select 'Time-window' on the frequency response graph and increase time-window value with small steps.
- A real-life example: speaker-boundary interference, floor-ceiling reflections.
Format: xls (Microsoft Excel 2003 Workbook)
Required software: Microsoft Excel 2003 or higher