Dynamic microphone and method of forming back-side air chamber

摘要

A dynamic microphone which prevents a wall forming a back-side air chamber from having a certain resonance frequency and effectively prevents the generation of standing waves in the back-side air chamber is provided. A dynamic microphone includes a dynamic microphone unit including a diaphragm configured with a voice coil and a magnetic circuit having a magnetic gap provided so as to allow the voice coil to vibrate, a bottomed case which is coupled to the dynamic microphone unit and forms a back-side air chamber communicating with back side of the diaphragm, and an acoustic resistance body which is pressingly attached in the case and composed of metal fiber including a pocket, an open cross sectional area of the pocket gradually decreasing toward the direction remote from the dynamic microphone unit.

主权项

1. A dynamic microphone comprising:
a dynamic microphone unit including a diaphragm including a voice coil and a magnetic circuit including a magnetic gap, the voice coil being disposed in the magnetic gap so as to vibrate; a bottomed case coupled to the dynamic microphone unit and forming a back-side air chamber communicating with a back side of the diaphragm; and an acoustic resistance body formed of metal fiber including a pocket and attached to an inside of the case, the pocket being formed to have an open cross sectional area gradually decreasing toward a direction remote from the dynamic microphone unit, wherein the pocket is a concave formed in the acoustic resistance body and having said open cross sectional area gradually decreasing from an upper portion of the acoustic resistance body in the direction remote from the dynamic microphone unit.