| 摘要 |
<p>A first feature of the present invention is that the opening of a sound output port (3b) is smaller in area than the opening of a sound input port (3a) in a horn (3). A second feature is that the sound output port (3b) of the horn (3) is located so as not to be in the way of a center axis of sound radiation from a speaker (2). A third feature is that a length L of the horn (3) is set at 370 mm or below. A fourth feature is that the horn (3) is gradually narrowed such that vertical sections thereof from the sound input port (3a) to the sound output port (3b) respectively have areas based on a predetermined rule.</p> |
