| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that a sound pressure level is decreased due to market demand for downsizing, weight saving, and compactification of a speaker.SOLUTION: A speaker is configured by forming a magnetic circuit into a non-circular shape, thereby improving a space factor, and providing a notch in an upper plate and/or a lower plate so that the plates or plate has an outer diameter smaller than that of a magnet. As a result, magnetic leakage flux from the magnetic circuit to outside is reduced and the magnetic flux to a magnetic gap is concentrated, thereby the magnetic efficiency of the magnetic circuit is improved and a sound pressure level is enhanced as a result. |
