FURTHER INVESTIGATION ON ACTIVELY CREATED QUIET ZONES BY MULTIPLE CONTROL SOURCES IN FREE-SPACE

Further research on the quiet zones created in the free space, using m ultiple control sources and error microphones located in two parallel planes, indicated that there also exists a range of optimal spacing fo r the control sources and error microphones. Both the computer simulat ions and experimental results show that the control system can create the largest quiet zone and suffer the least increase of total sound po wer output when the control actuators and sensors are arranged within this optimal range. (C) 1997 Acoustical Society of America.