Mobile acoustic reproduction apparatus

Abstract

A center loudspeaker is disposed near the middle between the left channel loudspeaker arranged at the front left side of the compartment and the right channel loudspeaker at the front right side, and this center loudspeaker transforms into a sound by the level-controlled signal of the sum of the acoustic signals of the right and left channels, and phase- and level-controlled signals of the acoustic signals of the right and left channels. As a result, the sound field is localized in the front of the listener, and right and left symmetrical wide-spread sound fields may be composed. Additionally, tweeters are disposed outside the right and left channel loudspeakers, and the mounting angles of the tweeters are adjusted so that the sounds released from the tweeters may be at an equal sound pressure level between the listener at the driver's seat and the listener at the front side seat. As a result, the drift of the sound field in the medium and high sound ranges may be eliminated in a simple structure, and right and left symmetrical wide-spread sound field are composed. Furthermore, corresponding to the opening or closing state of the window glass or seated position, by controlling the phase and level of the sounds released from the loudspeakers and the tweeters, sound fields always symmetrical to the listening position and spread widely may be composed.