Design and implementation of a car cabin personal audio system

With the individual requirements of different occupants and the proliferation of audio sources in the automobile, there is an interest in implementing independent front and rear listening zones to match the preferences of the occupants. Because simulations showed the physical limits for creating personal listening zones, low- and high-frequencies arrays were considered separately. Four standard audio loudspeakers were used for frequencies below 200 Hz, and phase-shift loudspeaker arrays mounted at the headrests were used for frequencies above 200 Hz. The split-band technique avoids the need for full-bandwidth loudspeakers in the headrests. To validate the results a personal audio system was implemented in an automobile cabin using the dual arrays; performance was consistent with the simulations. A contrast of 15 dB between bright and dark seats was possible.