| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a speaker device of simple structure which solves various problems caused by the air sucked and discharged through a bass reflex port. <P>SOLUTION: A bass reflex port 10 consists of a main tube part 100 and air flow straighteners 101, 102 placed at both ends of the main tube part. The main tube part 100 is in the shape of circular tube having a constant circular hollow cross section that has an inside diameter and a length required for exciting Helmholtz resonance at a desired frequency. The air flow straighteners 101, 102 are formed so that the hollow cross-sectional area increases gradually from the side connected to the main tube part 100 toward the opposite side. The air flow straighteners 101, 102 are formed so that the interval between a pair of wall surfaces, out of a group of two pairs of wall surface facing each other, is constant, and the hollow cross-sectional area of the other pair of wall surfaces increases monotonously according to an exponential function. <P>COPYRIGHT: (C)2012,JPO&INPIT |
