| 摘要 |
PURPOSE:To improve low sound production by so forming a bass-reflex cabinet duct formed by changing the length up to the center of a speaker unit as to partially cover the front of the speaker unit. CONSTITUTION:A speaker unit 1 which is mounted to a baffle board 2 is contained in a speaker cabinet 3 and protruding plates 5 having curved form (e.g., expotential curve form) ends are mounted to the top and bottom of the front of the unit 1 by leaving a fixed spacing from the baffle board 2, whereby a bass-reflex cabinet duct 4 is formed. The abovementioned bass-reflex cabinet duct is shorter in length as it goes apart from the central direction of the speaker unit and therefore the resonance frequencies by the duct are distributed and the characteristics of low frequency range become broader and milder. On the other hand, the protruding plates 5 are mounted so as to partly cover the speaker unit 1 and therefore the frequencies above the resonance frequencies are cut off and will not be radiated from the opening. |
