| 摘要 |
PURPOSE:To flatten a sound pressure pattern by converging acoustic power by forming a couple of upper and lower or right and left flanks in parallel not less than a half as long as the overall horn length from the throat part and by spreading the remaining parts in an exponential or catenary curve shape. CONSTITUTION:Left and right wall surfaces 7 and 8 of the loudspeaker horn extend in parallel from throat 9, not less than a half the overall horn length corresponds to this parallel part 10, and exponential-curve-shaped part 11 is formed continuously from the parallel part 10 to square opening part 12. The opening angle of this curve- shaped part 11 connected by a straight line is thetaH. Further, upper and lower wall surfaces 13 and 14 are formed in the exponential curve shape from throat 9 to opening part 12 and the angle formed of the straight line connecting throat 9 to opening part 12 is thetaV. In the above-mentioned constitution, acousting radiation power can be converged within a constant directional angle and a sound pressure characteristic pattern within the directional angle can be made constant and flattened, so that the directional angle control range with a less change in sound quality can be widened. |
