Abstract:
To provide an insulator, which supports a fixed pole in a unidirectional condenser microphone in a shareable manner among microphones that are different in the distance between acoustic terminals from one another. Coarse adjustment is performed on an insulator 31 including a plurality of sound holes 32 drilled therein by acoustically closing a predetermined sound hole 32 among the plurality of sound holes 32 by a predetermined sound hole closing means, and fine adjustment is performed by applying a predetermined amount of compressive force to an acoustic resistance member 40 by an acoustic resistance adjusting means 50 (adjustment nut 51), so as to adjust acoustic resistance present in a sound wave passage from a rear acoustic terminal to the back of a diaphragm.
Abstract:
In a unidirectional dynamic microphone unit, a cylindrical tube is provided to cover the microphone unit, a cylindrical wall of a first cylindrical portion that is included in the cylindrical tube and extends to at least the rearward is provided with a rear sound wave introducing portion weighted such that an acoustic resistance value is gradually made smaller toward the rearward side from positions of sound holes for taking in a sound wave transmitting around from the rearward side, preferably formed of a trumpet-shaped opening, and it is possible to enhance the sensibility to sound pressures without degradation of the frequency response and the directionality.
Abstract:
A microphone holder holds a microphone in which an upper surface and a lower surface of a step portion are formed on an outer surface of a housing, and the microphone holder includes: a holder which is formed in a cylindrical shape having openings on upper and lower sides and in which a plurality of through passages penetrating a wall of the cylindrical shaped body is provided; a sliding portion provided movably in a circumferential direction along the openings of the holder; a lock ring configured to cover the through passage formed to the holder, from an outer side by a lock plate extending from the sliding portion; and a contact member which is movably held in the through passage and can contact on an upper surface side of the step portion of the microphone.