Improvement on performance and stability with multiple secondary speakers in duct ANC system

A multi-channel duct active noise control(ANC) system is investigated in this paper with both theoretical and experimental studies. An optimized method to minimize the total sound power in a duct is proposed to determine the positions of secondary speakers and error sensors. The validity of theoretical calculation results is proved on a practical duct platform, and the experimental results indicate that remarkable improvements can be achieved on both noise reduction and system stability with the multiple secondary speakers rather than a single secondary speaker.