Car Interior Sound Field Zoning Using Optimal Loudspeaker Array and Double Iteration Method

Car interior sound field zoning is receiving increasing attention. The weighting factors are generally used to balance the acoustic contrast and the sound field reconstruction error of the sound field zoning control. However the weighting factors often need to be set at different frequencies, so it is complicated to operate, and the optimal control effect cannot be guaranteed in the whole frequency range concerned in a car. To solve the above problem, a car interior sound field zoning method with optimal weighting factors is proposed in this paper. Firstly, the mathematical model of the method combining acoustic contrast control and pressure matching under the constraint of the multi-loudspeaker driving signal is established. Then, the optimal loudspeaker array is obtained by using the genetic algorithm. After that, the optimal weighting factor of each frequency is obtained by using the double iteration procedure. Finally, to verify the method proposed, a sound field zoning control system was built in a car, and the experimental results show that the broadband average acoustic contrast between the bright zone and dark zone in the car is greater than 20 dB, and the average sound field reconstruction error in the bright zone is less than -7 dB.