Full-scale outdoor concert adaptive sound field control

Outdoor musical events in urban environments is of large cultural importance, but is also a source of noise, especially for non-participating neighbors. In an attempt to solve this, an Adaptive Sound Field Control (ASFC) system is under development. The purpose is to mitigate low frequency noise annoyance and simultaneously enhance the musical experience of the audience. The system uses a secondary array of loudspeakers, canceling out the sound in a dark zone. To do this, accurate estimates of the transfer function between the loudspeakers and the dark zone is necessary. A static version of the system has been tested in three events: a controlled pre-test, the KappaFutur Festival in Turino, and Tivoli in Copenhagen. These deployments are reported and discussed, with special focus on the KappaFutur Festival, where noise measurements where conducted in the neighborhood, supplementing the insertion loss measurement the ASFC. The performance of the ASFC system is shown to strongly depend on the complexity of the setting. In the final stage, the system needs to be adaptive in order to adjust for changing climate conditions. The adaptive parts of the system is under development, and will be tested in a series of events in 2019.