Active and passive orchestra shells and stage acoustics

This spring the largest theater building of The Netherlands, the Chasse Theatre at Breda, was completed. Of the two main auditoria, which have similar stage houses, one has electronic variable acoustics by means of a SIAP system, including a stage system, and the other has mechanical variable acoustics which includes a large orchestra shell. It will be shown through measurements that active (electronic) stage acoustics can be at least as effective as passive (physical) stage acoustics. It is particularly interesting that loudness, reverberation time, and reflection patterns can be influenced independently with active systems. This flexibility is an advantage for meeting the needs of performers. Furthermore, active control of stage acoustics can also provide a significantly improved foldback to actors and singers for drama, opera performance, etc. when technical stage facilities and scenery make physical acoustic means difficult to apply. Since acoustic coupling of the stage to the auditorium main volume is an important factor, results will also be presented of the achievements of the SIAP system to correct auditoria which have spaces with (extremely) poor acoustic coupling such as balcony and under balcony areas. The orchestra pits, which are of different size and shape, but have the same passive acoustic treatment, will be compared.