Active control of automobile cabin noise with advanced speakers

Abstract

The purpose of this presentation is to demonstrate the application of active control of engine noise in the interior cabin of a sport utility vehicle with advanced, compact piezoelectric sound sources. A broadband feedforward filtered-X LMS algorithm has been used to achieve this goal. Preliminary tests have been conducted using arrangements of up to four commercially available speakers and four microphones. Various reference signals have been studied and these configurations show good results; attenuation of 7 dB at the error sensors has been measured in the 40–500 Hz frequency band and the dimensions of the zone of quiet generated by the control has also been measured. The ultimate goal of the research is the implementation of the active noise control with a new generation of speakers. These speakers use piezoelectric devices to induce the displacement of a speaker membrane, which radiates sound. Their main advantages are weight and dimensions, which are significantly smaller than conventional speakers are. [Work supported by MSI/ONR.]