| 摘要 |
<p>Desired pressure-frequency characteristics can be acquired by enlarging the back space (20S) of a diaphragm (21) properly, and a mechanical connecting portion for a speaker unit (1A) can be retained at a yoke center portion. The speaker unit (1A) comprises a frame (10), a vibrator (20) supported by the frame (10), and a magnetic circuit (30) for driving the vibrator (20). The magnetic circuit (30) includes a first magnetic member (31), a second magnetic member (32) and a magnet (33). A magnetic gap (30G) is formed in the clearance between the first magnetic member (31) and the second magnetic member (32). The vibrator (20) has the diaphragm (21) covering the first magnetic member (31). This first magnetic member (31) has such an annular air chamber (31A) as is opened to the space covered with the diaphragm (21).</p> |
