Improving sound qualities at the seats under deep balcony overhangs

Abstract

Source‐receiver distances in a large hall could be reduced by increasing the balcony overhangs, which, however, may cause insufficient acoustical energy for the under‐balcony seats. Besides, the reduction in the sense of reverberation cannot be easily mitigated. In this research various design strategies, including utilizing the technique of a flying balcony, were examined in a 1550‐seat hall with deep balcony overhangs. Both BEM simulation and scale model measurements were performed. Optimizing the profile of the under‐balcony space and utilizing ceiling and side reflectors near the platform were effective in enhancing early reflection. This is especially meaningful for high‐frequency string sounds that radiate against the ceiling. Opening the rear part of the balcony that formed a partially flying balcony could compensate late reflections. Preliminary scale modeling results showed that approximately 15% increase in early decay time can be achieved with carefully designed ceiling geometry when the opening area was only 7% of the overhang area.