| 摘要 |
PURPOSE:To give the same frequency characteristic and sound image localization as a front seat to a rear seat by providing a speaker system, which limits the radiation area of an acoustic power, for the rear seat. CONSTITUTION:Four directivity control speaker systems 4 to 7 which have sharp directional patterns to limit the radiation area of the acoustic power are provided per channel in parallel for two listeners in front seats and those in rear seats. A digital filter 8 which is provided with a coefficient to correct the time of the response from a speaker system 3 for low-pitched sounds and to cancel the response from speaker systems 4 and 5 for high-pitched sounds for listeners in front seats is provided in the preceding stage of input to speaker systems 6 and 7 for high-pitched sounds for listeners in rear seats. Thus, the time response from the speaker system 3 for low-pitched sounds is matched even in listening positions of rear seats, and the acoustic field characteristic which is not affected by the response from speaker systems 4 and 5 for high- pitched sounds for listeners in front seats is obtained. |
