Acoustical analysis of a variable roof configuration concert hall: The São Paulo Hall

The São Paulo Hall (SPH) is recognized by musicians and musical critics in general by its good acoustical quality. It has, as an important feature, variable acoustics due to its movable roof, which is employed by musicians to tune the room according to the musical style. This work addresses the acoustical quality of SPH and its dependence on the roof configuration. Impulse responses for one source, eight microphone and two dummy head positions, using the sweep‐sine technique with pre‐emphasis, were obtained for seven roof configurations. Some details of the measurement procedure to ensure good accuracy are discussed. The measurement results were then used to compute the main room acoustical quality parameters, for each octave band between 63 and 8000 Hz. The spatial average and deviation of these data are presented as a function of the frequency band. The influence of the roof configurations on the obtained acoustical parameters is also discussed. Furthermore, comparative plots among SSP at the chosen roof configurations and two famous and representative halls from the classical and romantic periods are reported and discussed. It is concluded that the movable roof is very effective in modifying the room acoustics and that the musician's choices are quite good.