| 摘要 |
PROBLEM TO BE SOLVED: To form an optimal sound field by mixing an output signal from a front seat signal phase shifter with an output signal from a rear seat signal phase shifter by adjusting each signal level, and outputting it as a middle seat signal to a middle seat speaker. SOLUTION: Signals FL1 and LR1 for a front seat and signals RL1, FR1 and RL1, RR1 for a rear seat from a head unit 1 are inputted to an amplifier unit 11 for operating the distribution processing of sound signals to each speaker and power simplification. The amplifier unit 11 generates front seat reproduction signals FL2 and FR2 for front seat speakers FLS and FLR, middle reproduction signals ML2 and MR2 for middle seat speakers MLS and MLR, and rear seat reproduction signals RL2 and RR2 for rear seat speakers RLS and RLR from the inputted signals FL1 and FR1 and signals RL1 and RR1. Then, sound signals power-amplified by power amplifiers 10F, 10M, and 10R for each speaker are outputted to an automobile compartment as a sound from the speaker of each seat, and the unnecessary attenuation of the sounds can be prevented. |
