# 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.

Software features:

- 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**.

Version: 1.02.

Format: xls (Microsoft Excel 2003 Workbook)

Required software: Microsoft Excel 2003 or higher

License: freeware

Download

Format: xls (Microsoft Excel 2003 Workbook)

Required software: Microsoft Excel 2003 or higher

License: freeware

Download

See also:

Room Boundary Simulator

Speaker Directivity Simulators