| 摘要 |
<p>PURPOSE:To secure the flat sound pressure frequency characteristics at the hearing point by selecting properly the shape and the size of the speaker box and the attaching position of the speaker. CONSTITUTION:The band cut-off filter is connected to the front step of the speaker 7, and at the same time the band pass filter is connected to the front step of speaker 8 each. Thus the dip is not caused by the reflected waves on the floor surface and at the hearing point. In case some dip is caused to the sound pressure frequency characteristics owing to the interference produced by the path difference between the rear wall reflected wave which is radiated from speaker 7 and reaches the hearing point after reflected on rear wall 9 of speaker box 5 and the direct wave which is radiated from speaker 7 and reaches directly the hearing point, the shape and the size of box 5 are determined so that the path difference between the rear wall reflected wave and the direct wave may be almost equal to that between the floor surface reflected wave and the direct wave. And speaker 8 is attached to such area that no dip may occur even with th frequency to cause the dip. As a result, no dip is produced by the rear wall reflected wave and in terms of the sound pressure frequency characteristics.</p> |
