| 摘要 |
PURPOSE:To obtain an invariably excellent acoustic characteristic by providing the 1st correcting means which corrects the high-frequency side power spectrum of a speaker in a frequency range higher than a frequency where the high-frequency side power spectrum begins to decrease and the 2nd correcting means which corrects the waviness of frequency characteristics in a frequency range lower than the frequency. CONSTITUTION:A correcting circuit 12 for front seats and a correcting circuit 13 for rear seats have basically the same constitution. The correcting circuit 12 has the 2nd high frequency correcting circuit 15L and a correspondence correcting circuit 16L for the number of person in the automobile. The 2nd high frequency correcting circuit 15L is a boost circuit which corrects a high frequency characteristic varies according to the kind of the automobile owing to a difference of the sound absorber in the automobile and consists of, for example, a differential amplifier 15A, resistance R5, capacitor C2, and variable resistance VR. The 2nd high frequency correcting circuit 15L and the 1st high frequency correcting circuit 10 constitute the 1st correcting means which corrects the power spectrum, and the both cooperate with each other to flatten the frequency characteristics in the automobile almost over the entire range. |
