| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a speaker device which can heighten directivity without having to install a band-limiting filter. <P>SOLUTION: In a speaker device to produce an amplified sound from an acoustic signal, a first speaker unit 101 and a second speaker unit 102 are placed nearby, with their diaphragms facing opposite directions. A first resonance tube 103 is a hallow resonance tube which is joined at one end to the diaphragm of the first speaker unit so as to cover it and is left open at the other end. A second resonance tube 104 is a hallow resonance tube which is joined at one end to the diaphragm of the second speaker unit so as to cover it and is left open at the other end. The interval between the open end of the first resonance tube and that of the second resonance tube is made to be a prescribed value. A supply part supplies acoustic signals which are 180 degrees out of phase with each other to the first speaker and the second speaker units. The overall length of the first resonance tube and that of the second resonance tube are made to be 1/2 of the prescribed value. <P>COPYRIGHT: (C)2013,JPO&INPIT |
