100m/s in case of music-based auditoriums causes echo. The time delay in this project is high, therefore, the rear walls are made the main absorbing material.
Sound shadow: The region concentrated mainly in the settings beneath the gallery experiences the sound shadow. This is because of two main reasons- the distance between the sound source and the last row of seats is too much and the region lies below the gallery causing a difference of 4-5dB, the solution to this is, installing speakers in the last tier of seats on the ground floor.
Materials used: As concrete is highly reflective, a 20mm thick polished timber is installed over it causing greater sound absorption. The back wall is treated with acoustic fabric fiberglass panels and the ceiling is plastered for sound dispersion. Velour acoustic curtains are used backstage. These curtains reduce outdoor noise as well as back stage noise by reducing damper sound waves. Pleated curtains are used that have deep pleats. These pleats ensure more sound Figure 39: Sound shadow
absorption.
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