MEMS Speaker Damping Mesh Reduces Total Harmonic Distortion
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Solution Overview
Problem
MEMS speakers experience increased total harmonic distortion due to vibration, affecting their performance, which existing designs have not adequately addressed.
Innovation Solution
Incorporating a damping mesh with an acoustic impedance value of 1 Mrayl - 500 Mrayl, connected to a through hole in the printed circuit board, to reduce resonance and improve sound transmission, along with a shell structure that includes a communication hole covered by a dust mesh to enhance low-frequency response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a MEMS speaker chip vibrates to make sound, then sound output is achieved, but total harmonic distortion increases
Solution Approach 1:
The patent introduces a damping mesh as an intermediary component between the sounding assembly and the external environment. This damping mesh acts as a mediator that selectively dampens unwanted resonant frequencies while allowing desired sound frequencies to pass through, thereby reducing total harmonic distortion without compromising sound output capability
Solution Approach 2:
The patent modifies the acoustic environment by introducing a damping structure with specific acoustic impedance properties. By changing the physical parameters of the acoustic path (adding damping mesh with controlled porosity and flow resistance), the resonant characteristics of the speaker chip are altered, reducing harmonic distortion across the operating frequency range
2Manufacturing precision
If resonance is reduced to improve sound quality, then total harmonic distortion decreases, but device structure becomes more complex
Solution Approach 1:
The patent employs a damping mesh made of porous material with specific flow resistance characteristics. This porous structure provides effective acoustic damping to reduce resonance and total harmonic distortion while maintaining a simple geometric form factor. The porosity and surface area of the mesh create acoustic drag that dampens resonant vibrations without requiring complex active control mechanisms or multi-component assemblies
Solution Approach 2:
The damping mesh is implemented as a simple, inexpensive passive component that can be easily integrated into the speaker assembly. Rather than using complex active resonance cancellation systems with multiple sensors and actuators, the patent employs a straightforward porous mesh structure that achieves resonance control through passive acoustic damping, significantly simplifying the overall device architecture
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The damping mesh effectively suppresses total harmonic distortion and sound pressure level resonance peaks, improving the overall performance and reducing the volume of the MEMS speaker.
Implementation Method 1
an acoustic impedance value of the damping mesh is in a range of 1 Mrayl - 500 Mrayl
Implementation Method 2
the damping mesh effectively suppresses total harmonic distortion and sound pressure level resonance peaks
Implementation Method 3
speakers mainly convert electrical signals into sound signals
Implementation Method 4
when it vibrates to make sound
Data Source
AI summary
The present disclosure discloses a MEMS speaker including a substrate with a cavity and a sounding assembly connected with the substrate, the substrate comprising an outer surface away from the cavity and connected with the sounding assembly, a top surface opposite to the outer surface and a side surface respectively connected with the outer surface and the top surface; a printed circuit board with a through hole and connected with the outer surface of the substrate; a first shell connected with the top surface of the substrate; and a damping mesh covering the through hole and connected with the printed circuit board; wherein sounds emitted by the sounding assembly transmit outward through the through hole and the damping mesh. Compared with the related art, MEMS speaker disclosed by the present disclosure has a better reliability.