| 摘要 |
A loud speaker is installed on the rear plane of a baffle board facing an opening within the baffle board which opening in cross section takes the form of a narrow forwardly directed cone and an annular acoustic resistance member which is triangular shaped in section is fixed to the cutting plane of the opening. Alternatively, a ring member which narrows in a forward direction to form a forwardly narrowing cone in cross section is fixed to the front of a loud speaker flange and fits within a baffle board opening with the flange installed on the rear plane of the baffle board. An annular acoustic resistance member of triangular cross section is fixed to the inside surface of the forwardly narrowing ring or to the front surface of the loud speaker flange internally of the ring. |
