Sound Waves Between Two Walls
Version: 1.03 (2019-08-12)
Software platform: Microsoft Excel
As the title says, this software calculates 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). Only the first eight reflections are computed (per wall).
This software is suitable for studying the following cases:
- Steady state and transient analysis of standing waves between two parallel walls.
- The effect of speaker and microphone placement (listening position) on the first reflections (use time-windowed response (<10 msec) to see the comb filter).
- 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 analyzed, but the opposite - how the sound pressure builds up. For this, select 'Time-window' on the frequency response graph and increase time-window gradually from zero.
- A real-life example: floor-ceiling reflections (or other 'two-wall' speaker-boundary interference).
Format: xls (Microsoft Excel 2003 Workbook)
Required software: Microsoft Excel 2003 or newer