Automatic audio parameter setting

Abstract

As with all listening spaces the interior of a car has acoustic effects that degrade the quality of reproduction of the audio system. To make this sound more natural and ultimately more enjoyable, an equaliser with variable parameters can be used to improve the frequency response. At present these parameters have to be set manually using laborious trial and error. Close to production start,time efficienty is most important and automation of this process would be very helpful. An attempt was made to determine the parameters automatically, but it was found to be almost impossible because they are based on skill and experience rather than on documented theory or principals. To fulfil the original aim a different approach was taken to visually assist the current methods. A software application was developed to graphically experiment with settings using a model of the equaliser applied to measurements of the cars frequency response. The results show the model agrees very well with the effect of the equaliser and the application performs its intended task efficiently. With a subwoofer module present one should be careful interpreting measurements. The present equaliser model does not compensate for the subwoofer. It is recommended to be modelled separately.