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Introduction & Project Overview
This application example briefly showcases the key points of an acoustic design aiming to provide high quality of speech events in the auditorium of Fondazione MAST. For the MAST multi-functional-complex it was particularly important for this venue to ensure the auditory experience at the highest standard.
Challenge
The sound system for the auditorium had to be designed to provide sufficient speech intelligibility. The room had a volume of approximately 2500 m³ and a RT of 1.2 s. Challenges included the fact that the ceiling was very reflective and the seats were covered in leather rather than fabric, which further increased the reverberation level. The room had to be modelled, then the right sound system designed and optimized for STI.
Project Execution & Results
After evaluation, simulation and decision making, the final sound system was planned as two main loudspeakers on the sides and four front fills mounted in the center. The main loudspeakers were steerable columns (2x K-array KH7), which were first configured using AFMG's advanced FIRmaker beam-shaping technology to direct as much sound energy as possible onto the audience and nowhere else in the room, thereby already significantly increasing the STI. In a second step, the unique STI Optimizer function of EASE 5 was applied to optimize the signal level against the negative influence of both signal masking and HVAC background noise. This allowed maximum speech intelligibility to be achieved with minimum effort, and it was nice to see the exceptional accuracy of the results confirmed by on-site measurements.
The resulting simulated direct SPL was 62 dB (A) with a standard deviation of 1 dB which corresponds to a high uniformity. The resulting STI was 0.63 with a standard deviation of 0.02. These results could not be achieved with conventional, non-steerable loudspeakers.
Measurements were conducted with STIPA signal in the twelve selected positions. The match between simulated STI and measured STIPA is very good, the results are the same within the established uncertainty of only 0.02 and in fact within the just noticeable difference (JND) of 0.03. The comparison is shown in the image slider.
Special thanks to Alessandro Saudelli for assisting with the auditorium project as well as Planet Service and K-array.
Learn more about FIRmaker and STI optimization following the links.