Active field control for piano room

Active field control (AFC) is an innovative system that employs electroacoustic technologies enabling ‘‘natural changes’’ to major auditory impressions, such as reverberance, loudness, and spaciousness. This talk presents typical design concept of AFC application for a piano room with a low ceiling in architecture and with a miniconcert in program. The aim is to accommodate a condition appropriate for both a solo piano performance and a miniconcert, regardless of the low ceiling height and significant increase of absorption by the audience in a miniconcert. This can be realized by using an AFC system, which converts the room into different acoustical conditions as follows. One is that AFC alters acoustics of the designed space, and makes it sound as if it has a higher ceiling, which leads to a longer reverberation. The other is negative absorption to compensate added absorption with the audience for a miniconcert. In the presentation, these technologies will be presented, along with the acoustical data.