| 摘要 |
PROBLEM TO BE SOLVED: To provide an array speaker system the directivity of which is enhanced by decreasing a difference of a directivity distribution shape between high and low frequencies. SOLUTION: An LPF 2 and an HPF 5 separate an input acoustic signal into low and high frequency signals. A delay circuit 3 provides a delay corresponding to a desired focal position to the low frequency signal by each speaker unit and thereafter multipliers 4-n, 4-n+1 provide a weight by a window function L for the low frequency signal to the resulting signal. A delay circuit 6 provides a similar delay to the high frequency signal and thereafter multipliers 4-n, 4-n+1 provide a weight by a window function H for the high frequency signal to the resulting signal. Corresponding adders 8-n, 8-n+1 sum outputs of the multipliers and thereafter the sum is outputted from speaker units 1-n, 1-n+1 via an amplifier 9-n, 9-n+1. The window function L for the low frequency is more relaxed than the window function L for the high frequency, resulting in that a difference of the directivity between the low and high frequencies is decreased. COPYRIGHT: (C)2005,JPO&NCIPI |
