Measurement and Possible Solutions of the Non-uniform Sound Field in the Automotive Industry

A high-quality car sound system is important for comfortable listening. At the present, the sound systems in the automotive are realized using multiway loudspeaker systems positioned at different distances of the listening positions. This different placement of the loudspeakers causes strong non-uniform frequency distribution of the sound field. The possibility of the placement of the loudspeakers into the optimal position in the car is limited and very often it is not possible. Thus, it is necessary to solve the consequences of the inappropriate position of the loudspeakers on the sound field using sophisticated digital signal processing.In this paper, we focus on the measurement of the distribution of the sound field in various listening positions in the car. Attention is also paid to the compensation of the non-uniform sound field. Primarily, these compensations can be performed using the frequency and dynamical corrections. Another option is to change the delay of the signal for each loudspeaker separately.This topic is very complex because the listening positions are placed in the near field of the multiway loudspeaker systems, where the distances between the loudspeakers are often close to or larger than the distance between the listening position and the loudspeaker.