Considering source directivity in a recital hall with seats surrounding the platform

Abstract

The impact of source directivity can be significant for chamber music performances, in particular for arena-type halls that have visual intimacy. This study has been carried out to understand the physical and perceptual aspects of the seats surrounding the platform in recital halls. Effects of architectural features were evaluated using computer simulations that accounted for source directivity and diffusive reflections. Both live and recorded subjective evaluations of chamber music performances were made in an actual hall while acoustical measurements were also taken. As a result, computer simulations using a singer source showed significant decrease in both clarity and strength in the 2-kHz band for the seats surrounding a centered platform. A wall 6 m in front of the platform was effective in mitigating the problems. Sound levels calculated from the recordings taken from various viewing angles were correlated with subjective evaluations, especially in the high frequencies. Timbre appeared to be the principal factor influencing solo performances and balance was the most important in judging ensembles. Nevertheless, live evaluation showed no significant difference among the listening positions.