In 1995 the new municipal theatre in the city of Deventer opened to replace the outdated old theater. The new building comprises a 780 seat main hall: a proscenium theatre with a large and fully equipped fly tower. A flat floor 216 seat multipurpose studio theatre with retractable seating serves as the small hall. A wide range of theatre and music types is programmed in the main hall, such as (unamplified) drama, musicals, theatre shows, musicals, opera, classical ballet, chamber music and symphony orchestra. It is one of the main concert venues of the East-Netherlands Orchestra. Furthermore, the Deventer Chamber Music Foundation programs its annual seasons of top-level recitals and ensembles in the main hall, because of its fine acoustics and seating capacity. Needless to say that variable acoustics are mandatory to facilitate optimum acoustics for each purpose. The auditorium is designed with a natural Reverberation Time (RT) close to 1.0 second for drama and all types of amplified sound. The side walls of the fan-shaped seating arrangement have architecturally integrated diffusion to achieve a uniform coverage of early lateral reflections throughout the entire seating areas (stalls and balcony).
For unamplified music (opera, classical ballet, chamber music, symphony orchestra, choir) an electronic acoustic architecture system was prescribed. Its installation by SIAP was an instant success, both among audiences, artists and the theatre’s management. In 2016 the SIAP Mk III processor was upgraded to the Mk IV. Annual preventive maintenance is taken care of on a contractual basis. An upgrade like this is limited to exchanging the “old” processor with the new version and – in this case – renewal of the amplifiers to secure that the entire system performs the same as a new one. It is a major cost saving that loudspeakers, racks, cabling etc. do not need to be renewed. In other words, a SIAP upgrade is economically interesting and does not involve (time consuming) installation work in the auditorium.
Since the processor upgrade a season of chamber and symphony concerts took place. The Chamber Music Foundation describes the result as “a very good acoustic”. The musicians express themselves unanimously very content with the acoustics. After these concerts the visitors speak enthusiastically with foundation members about the renewed acoustics. Similar responses are usual after other theatre and concert performances, rehearsals etc.