Moving-coil loudspeaker with area-alterable capacitive vibration sensor

Abstract

The invention provides a moving-coil loudspeaker with an area-alterable capacitive vibration sensor, of which the magnetic path structure is an outer magnetic path or an inner magnetic path. A coil is wound on a conductive voice coil framework to form a voice coil, a capacitive / moving signal converting circuit is provided, the area-alterable capacitive vibration sensor positioned in the same axial direction as the conductive voice coil framework and used for measuring the displacement of the voice coil is arranged between a magnetic-conductive column and a magnetic-conductive upper plate, and capacitance variable output by the area-alterable capacitive vibration sensor is transmitted to the input terminal of the capacitive / moving signal converting circuit. As the capacitance value of the area-alterable capacitive vibration sensor and the displacement of the voice coil form a linear relationship, wide-range linear output is achieved, and the measurement requirement of a large-amplitude highly-dynamic low-frequency loudspeaker is particularly satisfied; and a moving signal of the loudspeaker voice coil can be obtained through detecting the output of the sensor by the capacitive / moving signal converting circuit to serve as a feedback signal to be input into the feedback input terminal of a moving servo amplifier, so that the closed-loop control of the loudspeaker is realized.

Description

technical field [0001] The invention relates to the technical field of loudspeakers, in particular to a dynamic-coil loudspeaker with a variable-area capacitive vibration sensor. Background technique [0002] The distortion degree of digital audio source and power amplifier in the playback link of the electro-acoustic field can easily reach below 0.01%. However, the distortion of the speaker at the end of the sound reproduction link is generally greater than 1%, and the ultra-low frequency range reaches more than 5%, which becomes the bottleneck for further improvement of the fidelity of the sound reproduction system. [0003] According to the structure of the magnetic circuit, the dynamic speaker can be divided into two types: internal magnetic type and external magnetic type, and the internal magnetic type can be divided into axial magnetic circuit and radial magnetic circuit according to the magnetization direction of the magnet. The length relationship between coil and ...

AI Technical Summary

Problems solved by technology

[0006] (3) Transient distortion: The diaphragm is forced to vibrate under the action of the driving force of the voice coil. The vibration system has a certain mass and certain damping, and cannot quickly follow the rapidly changing input signal vibration, and there is always a certain delay. Time

This method has the following disadvantages: it takes a while for the sound signal to reach the pickup from the speaker, there is a long time lag in the feedback of the signal, and the phase relationship is complicated. Generally, the feedback cannot be added too deep, otherwise it will easily cause the system to oscillate.

It can be foreseen that this method is easily affected by the cone angle of the diaphragm as the reflective surface and the reflection characteristics of the diaphragm material. In its embodiment, ON2152 is used as the sensor. The specification of ON2152 lists the 90% reflection of white paper The Ic-D diagram reflected by the specular surface can prove that it is affected by the reflective surface, and its output linearity is not ideal

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