Diaphragm for speaker

Abstract

A small-sized diaphragm for a speakers exhibiting excellent acoustic performance can be obtained at low cost by mixing a cellulose-based powder, which has a particle size distribution of 5-500 m and is imparted with affinity to non-chlorine resins through a surface treatment such as esterification, to a non-chlorine resin in such an amount that the ratio of cellulose in the mixed material is 30-70 wt%.

Description

technical field [0001] The present invention relates to the structure of a loudspeaker diaphragm, which is a component having a function of emitting sound waves in a loudspeaker. Background technique [0002] In the past, as known, the main part of the loudspeaker includes an electromechanical transducer and a vibrating plate that converts electrical signal energy into mechanical vibration energy; The energy drives and vibrates, emitting sound energy. figure 1 It is a schematic diagram of the structure and peripheral parts of the vibration plate of such a general speaker. The voice coil 3 is installed in the center of the vibration plate 1, and the outer periphery of the vibration plate 1 is a flexible edge 2. In addition, the center of the vibration plate has a The baffles 4 with the same flexibility are held so that the central part can freely vibrate inside each frame (not shown). Next, the voice coil 3 is inserted into the magnetic field of the magnetic circuit (simila...

AI Technical Summary

Problems solved by technology

[0006] At this time, if the outer peripheral portion and the central portion of the vibrating plate 1 vibrate with the same phase at all frequencies, then in the usual audio range, the sound pressure frequency characteristic of the reproduced sound is flat and good sound quality can be obtained; The vibrating plate itself is also flexible, so if the driving frequency is increased, the phase near the outer periphery will be delayed relative to the central part, and at a specific frequency, the central part and the outer peripheral part will vibrate in reverse phase, and the emitted sound waves will cancel , a valley (ditpu) occurs in the frequency characteristic. In addition, at a certain frequency, the vicinity of the outer periphery or the natural part of the vibration plate resonates strongly to generate a peak, thereby degrading the sound quality of the reproduced sound.

In particular, the phenomenon that the vibrating plate 1 separates to generate resonance is generally an asymmetric bending vibration of the vibrating plate material, which mostly causes high-order harmonic distortion, and the shape and material of the vibrating plate are related to this split vibration. In particular, it has been It is known that the density, Young's modulus and tanδ (ie, the mechanical internal loss of the material) as representative physical property values ​​have a great influence on the frequency characteristics and the level of distortion, and it is gradually clear that the direction of these physical property values ​​is oriented. For realistic Material, in order to achieve technical requirements, make the frequency characteristics flat and obtain good reproduction sound quality, it is required to spend a lot of effort on the development of the diaphragm material when designing the speaker

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