Self-Supported Coil Headphone Transducer for Low Resonance
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Solution Overview
Problem
Conventional electrodynamic transducers for headphones face challenges in achieving low resonant frequency without using perforations, which leads to attenuation of low frequencies and distortion due to the weight of the coil support and membrane materials, limiting their ability to reproduce the full audio frequency range effectively.
Innovation Solution
A broadband electrodynamic transducer is designed with a stiff membrane made of aluminum or beryllium, coupled with a self-supported coil that eliminates the coil support, and a flexible suspension, allowing for a lightweight and high-frequency capable mobile part with a low resonant frequency, reducing or eliminating the need for perforations and increasing air decompression volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a conventional coil support structure is used, then the coil is mechanically supported and positioned, but the weight of the mobile part increases and resonant frequency increases
Solution Approach 1:
The invention extracts and removes the coil support structure from the transducer design. The coil is made self-supported through winding techniques that provide inherent mechanical stability without requiring an additional support structure, thereby eliminating the weight and complexity of the support while maintaining coil positioning and mechanical integrity
Solution Approach 2:
The invention merges the functions of the coil support and the coil structure itself by designing the coil to be self-supported. The winding pattern and tension of the coil provide both the electrical function and the mechanical support function that were previously separated into distinct components
2Adaptability or versatility
If perforations are added to the membrane, then low frequency reproduction is improved, but distortion increases and manufacturing complexity increases
Solution Approach 1:
The invention changes the physical parameters of the membrane by using a thin, flexible material with specific mechanical properties that allow it to function without perforations. The membrane's flexibility and tension are optimized to provide the necessary acoustic compliance and low-frequency response while maintaining structural integrity and minimizing distortion
3Object-generated harmful factors
If a stiff membrane material is used, then piston performance is improved and distortion is reduced, but the resonant frequency increases
Solution Approach 1:
The invention uses a thin film membrane that is flexible yet maintains sufficient stiffness for piston operation. The thin film design allows the membrane to move freely at low frequencies while maintaining structural integrity, achieving a balance between flexibility for low-frequency response and stiffness for distortion reduction
4Speed
If the mobile part is made lighter, then high frequency reproduction is improved, but mechanical strength decreases
Solution Approach 1:
The invention employs composite construction in the voice coil assembly, using lightweight materials for the coil former and winding that provide both reduced mass and sufficient mechanical strength. The composite design allows the mobile part to achieve high-frequency response capability while maintaining the necessary mechanical strength through material selection and structural design
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
This configuration enables the transducer to reproduce low and high frequencies with minimal distortion, improving dynamics and reducing weight, thus enhancing sound reproduction across the full audio frequency range without the need for perforations, resulting in improved sound quality and reduced latency.
Implementation Method 1
The motor has a groove, called air gap, into which enters the coil configured to sense the magnetic field so as to move in translation under the effect of the magnetic force on the current therein
Implementation Method 2
a membrane having a shape of revolution suited to transform the translational movement of the coil into an acoustic wave
Data Source
AI summary
The invention relates to a broadband electrodynamic transducer for headphones, said transducer comprising: —a magnetic motor designed to generate a magnetic field; —a coil that is disposed in the air gap of the magnetic motor and can move translationally under the effect of the magnetic field; and —a membrane that is connected to the coil in such a way as to convert the translational movement of the coil into an acoustic wave; —the transducer comprising a self-supporting coil that is glued to the membrane, the membrane having a Young's modulus of more than 40 GPa.