Brochure Title Author Date Journals PDF Active Field Control - - - Download Selected references Title Author Date Journals PDF Case study for voice amplification in a highly absorptive conference room using a negative absorption tuning by the Yamaha Active Field Control system. Takayuki Watanabe 2006.12 4th Joint Meeting of ASA/ASJ, Honolulu Download Acoustical Renovation Using Active Field Control in Preserving an Historical Auditorium Takayuki Watanabe, Shinji Kishinaga, Fukushi Kawakami 2004.4 ICA 2004, Kyoto Download Active Field Control (AFC) Reverberation Enhancement System Using Acoustical Feedback Control Hideo Miyazaki, Takayuki Watanabe, Shinji Kishinaga and Fukushi Kawakami Yamaha Corporation, Advanced System Development Center 2003.10 AES 115th Convention, New York Download Presentation Active Field Control in Auditoria Fukushi Kawakami & Yasushi Shimizu Acoustic Reserch Laboratories Yamaha Corporation 90 Applied Acoustics 31(1990)47-45 Download Recent Progress in AFC Technology -New ideas for averaging the loop gain- Fukushi Kawakami Acoustic Technology and Development Division Yamaha Corporation 99.03 AES Korea section The 2nd Audio conference Download AFC patent list Pat.No. Title Date of Pat. Contents 5,025,472 Reverberation imparting device 1991 Basic idea Feedback/FIR 5,131,051 Method and apparatus for controlling the sound field in auditoriums 1992 Energy exchange 5,642,425 Sound field control device 1997 EMR 6,072,879 Sound field control unit and sound field controll device 2000 YUME-HIBIKI including EMR & Fluc-FIR 6,157,724 Apparatus having loudspeakers concurrently producing music sound and ref 2000 Music instrument including EMR & Fluc-FIR Copyright (C)2008 Yamaha Corporation. All rights reserved.