| 摘要 |
PROBLEM TO BE SOLVED: To accurately correct sound characteristics, even when the number of taps is limited. SOLUTION: In a filter coefficient calculation apparatus 20, a gain correction characteristic calculation section 3 calculates impulse responses corresponding to a linear-phase filter having the inverse characteristics of gain characteristic of a reproduction system 17, clips the timely continuous impulse responses that include a peak value, whose number is identical to the preset number of filter taps from among the calculated impulse responses, and calculates the frequency characteristics of the impulse responses as the gain correction characteristic. A phase correction characteristic calculation section 4 calculates a phase correction characteristic by normalizing a gain characteristic of the inverse characteristic from the inverse characteristic of a frequency characteristic of the reproduction system 17, and a filter coefficient calculation section 6 calculates filter coefficients of the reproduction characteristic correction filter, from a synthetic correction characteristic obtained by combining the gain correction characteristic with the phase correction characteristic in a correction characteristic synthesis section 5. COPYRIGHT: (C)2008,JPO&INPIT
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