| 摘要 |
PURPOSE:To give damping to a minimum resonance peak caused on a sound pressure frequency characteristic in case of a constant current drive, by packing a magnetic fluid with a suitable viscosity in magnetic gap of a dynamic speaker. CONSTITUTION:A bobbin 9 wound with a voice coil on the outer circumference is inserted in a magnetic gap formed with a pole piece 6 and a yoke plate 7 and a magnetic fluid 5 with a suitable viscosity is packed around the voice coil 8. The bobbin 9 is fitted with a disc shape vibration diaphragm. This speaker is driven with constant current by a signal amplified with a constant current amplifier. |
