Equalization of low frequency response in automobile

Abstract

In automobile space, we experience sound coloring of reproduced sound quite differently from large spaces such as concert halls. This is assumed to be due to the well-separated acoustic modes in the low frequency range up to the relatively high crossover frequency. Such unwanted sound coloring can be reduced through equalization of the well-separated modes. However, it is not a simple process as binaural responses are different for every person and drivers are likely to move their head during driving. We introduce a novel approach, based on minimum phase inversion, to the equalization of the low frequency response in order to compensate for the coloring. We then compare the proposed approach with the conventional least squares based inversion and attempt to show the superiority of this approach through experimental and listening test results.