Benefield Anechoic Facility undergoes upgrade Published Jan. 4, 2021 By 412th Test Wing Public Affairs 412th Test Wing Edwards Air Force Base, California -- The largest anechoic chamber in the world just got even better. The Benefield Anechoic Facility on Edwards Air Force Base, California, recently underwent an upgrade to its massive turntable system to ensure they are able to continue to provide unparalleled testing services for the warfighter well into the future.