J. Warner Soditus
Graduate Program in Acoustics, Penn State Univ., P.O. Box 30, State College, PA 16804
The use of an energy density error quantity for adaptive filtered-x active noise control has been demonstrated to provide advantages over pressure squared control in a one-dimensional experiment [S. D. Sommerfeldt and P. J. Nashif, ``An Adaptive Filtered-X Algorithm for Energy-Based Active Control,'' J. Acoust. Soc. Am. 96, 300--306 (1994)]. The performance of energy-density-based control was further explored in comparison to pressure-squared control. By using two small microphones, the pressure and energy-density sensor was moved through regions of the upstream and downstream of the secondary source in a one-dimensional low-frequency harmonic sound field. Extensive data were collected for various sensor locations to demonstrate that the pressure-based control strongly depends on sensor location, while the energy-density-based control is more sensor location-independent.