| 摘要 |
PURPOSE:To achieve a measuring device for a speaker which can determine the optimum reference static location of an oscillation system, by measuring the change in a sound pressure frequency characteristics to the change in the reference static location of the oscillating system to a magnetic circuit. CONSTITUTION:A speaker 4 to be measured is connected to an amplifier 2 connected to an AC power supply 1 via a capacitor 3, and a series circuit of a resistor 5 having a sufficiently higher value than the impedance of the speaker 4 and a DC power supply 6 is connected in parallel with the speaker 4. In an anechoic room 7 in which the speaker 4 is measured, a microphone 8 is arranged opposingly to the speaker 4, and the output of the microphone 8 is recorded with a recorder 9. In measuring the sound pressure versus frequency characteristics of the speaker 4, a synthesized current of AC and DC flows to the speaker 4, and the oscillating system of the speaker 4 is oscillated by shifting the reference static location by the DC component. Thus, if the reference static location is optimum can be discriminated by comparing the sound pressure and distortion factor according to the amplitude of the direct current. |
