| 摘要 |
PURPOSE:To obtain a speaker unit capable of reducing the interference of sounds by disposing acoustic resistance paltes having plural holes on a front surface, rear surface or both surfaces of a diaphragm. CONSTITUTION:A front surface acoustic resistance plate 10 is fitted on a diaphragm 4 through a gasket 8. Plural small holes 20 and 21 are drilled on the resistance plate 10, and the diameter of the hole 20 at the center is larger than that of the hole 21. The total area of these holes is decided to be 20-30%. Plural holes 30 are drilled on a frame 5, and formed in a slender shape at same intervals along a periphery of a coil 2, thereby functioning as a rear surface acoustic resistance plate. By providing acoustic resistance plates before and after the diaphragm 4 in such a way, sounds in a low frequency can be escaped through holes formed around resistance plates 5 and 10, which is effective in canceling out of low frequency parts and makes turning-around smaller. |
