| 摘要 |
PURPOSE:To efficiently execute a measurement by a simple operation, by axially supporting the second arm to which a microphone whose angular displacement is free has been fixed, by the first arm whose angle is displaced round the axis, and moving each arm. CONSTITUTION:Length of a support 11 vertically provided on a front 6 of a loudspeaker means 1 is constituted so that it can be adjusted by an operating piece 13. On the upper end part of the support 11, one end part of the first arm 14 is axially supported so as to be freely rotatable by a bearing 15. The first arm 14 is driven for its angular displacement by a motor 18 round the axis on a virtual straight line 16. On the other end part of the first arm 14, one end part of the second arm 19 is axially supported, and is driven by a motor 20. To the other end part of the second arm 19, a microphone 7 is fixed. The first and second arms 14, 19 have the same curvature as a virtual spherical surface for measuring an acoustic characteristic, and have 1/8 circular arc length. When the motors 18, 20 are operated so as to be related to each other, the microphone 7 can be brought to an optional position on the virtual spherical surface centering around a reference point 5. |
