| 摘要 |
PURPOSE:To obtain a uniform directivity angle characteristic over a broad band and higher sound pressure characteristic by constituting the speaker to be a 1st section of the throat side and a 2nd section at the opening side and forming opposite side walls to be a specific shape. CONSTITUTION:A couple of opposite side walls 1, 2 consist of two sections being the 1st section at the throat side 3 and the 2nd section at the opening side 4 and each side wall curve depends on equation y=a+becx (where a, b, c are constants different from the 1st and 2nd sections). Through the constitution above, a higher sound pressure is obtained from the low frequency to the intermediate frequency in the frequency characteristic while keeping a uniform directive angle characteristic in the horizontal direction and the part of the side walls 1, 2 close to the opening is formed by a circular-arc so that a sound wave is more smoothly parted in the vicinity of the opening, the directivity angle is in general narrow and even when more accurate control is requested, the narrowing phenomenon is avoided. Thus, uniform directive angle characteristic over a broad band is obtained. |
