Inner Dual-Diaphragm Loudspeaker Core for Smooth High-Frequency Output

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Solution Overview

Problem

Existing speaker modules in earphones using moving coil vibration systems suffer from large vibration mass, poor transient characteristics, and asymmetric electromagnetic driving forces, leading to peaks and valleys in high-frequency response and compromised sound quality.

Innovation Solution

A dual-diaphragm assembly with a first and second diaphragm assembly driven by a magnetic circuit system, featuring a first and second voice coil, and a magnetic loop configuration that reduces thickness and enhances high-frequency sound quality, while maintaining performance across different frequency ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a moving coil vibration system is used, then the speaker module is cheap and technically mature, but the vibration mass is large and transient characteristics are poor

Engineering Contradiction:
Improvemanufacturing cost and technical maturityVSAvoidvibration mass
Core Design Contradiction:
Ease of manufactureVSWeight of moving object

Solution Approach 1:

The patent divides the single diaphragm into two separate diaphragms (first diaphragm and second diaphragm) that operate independently. Each diaphragm has its own voice coil and magnetic circuit, allowing them to function as separate vibration systems. This segmentation enables each diaphragm to have reduced mass while maintaining the benefits of mature moving coil technology.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a moving coil vibration system is used, then the structure is simple, but asymmetric distribution of electromagnetic driving force produces wag vibration and split vibration

Engineering Contradiction:
Improvestructural simplicityVSAvoidvibration stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent employs symmetric dual-diaphragm configuration where both diaphragms are positioned symmetrically relative to the magnetic circuit system. The first diaphragm and second diaphragm are arranged on opposite sides of the magnetic circuit, with identical magnetic portions surrounding each voice coil. This symmetric arrangement ensures balanced electromagnetic driving forces, eliminating asymmetric vibrations while maintaining structural simplicity.

Inventive Principle:
Principle #4Asymmetry

3Reliability

If high frequency response is improved, then sound quality expands, but the module thickness increases

Engineering Contradiction:
Improvehigh frequency response qualityVSAvoidmodule thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent transitions from a single-plane diaphragm configuration to a three-dimensional dual-diaphragm arrangement. The first and second diaphragms are positioned on opposite sides of the magnetic circuit system, utilizing the radial dimension. This spatial arrangement allows high-frequency response improvement through enhanced magnetic field interaction while maintaining compact overall thickness by distributing components in multiple dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Volume of stationary object

If a single diaphragm assembly is used, then the structure is compact, but the high-frequency response has serious peaks and valleys

Engineering Contradiction:
Improvemodule compactnessVSAvoidhigh frequency response smoothness
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The patent segments the single diaphragm system into two independent diaphragm assemblies, each capable of producing sound waves. The first diaphragm and second diaphragm operate simultaneously but independently, with their sound outputs combining to smooth out frequency response peaks and valleys. This segmentation maintains compactness while improving high-frequency response characteristics.

Inventive Principle:
Principle #1Segmentation

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 dual-diaphragm design improves sound quality by reducing the sense of timbre division and enhances performance in both low and high-frequency ranges without increasing the module's thickness, while maintaining a compact size.

Implementation Method 1

the first voice coil cooperates with the first magnetic portion and the second magnetic portion to drive the first diaphragm assembly to vibrate; the second voice coil cooperates with the second magnetic portion and the third magnetic portion to drive the second diaphragm assembly to vibrate

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP4387269B1Inner core of loudspeaker module, loudspeaker module and earphone
Publication Date: 2025.10.29 BEIJING HONOR DEVICE CO LTD
  • EP4387269B1 patent drawingFigure 1
  • EP4387269B1 patent drawingFigure 2
  • EP4387269B1 patent drawingFigure 3~4

AI summary

A kernel of a speaker module, a speaker module, and an earphone are provided and related to the field of electronic product technologies. The kernel includes a first diaphragm assembly, a first voice coil, a magnetic circuit system, a second diaphragm assembly, and a second voice coil. The magnetic circuit system includes a first magnetic portion, a second magnetic portion, and a third magnetic portion. The first magnetic portion surrounds a periphery of the second magnetic portion. The first voice coil cooperates with the first magnetic portion and the second magnetic portion to drive the first diaphragm assembly to vibrate. An inner side of the second magnetic portion includes an accommodating space, and the third magnetic portion is arranged in the accommodating space, and is spaced apart from the second magnetic portion. The second voice coil is fastened to the second diaphragm assembly, and the second diaphragm and the first diaphragm assembly are respectively arranged on two opposite sides of the magnetic circuit system. The second voice coil is a planar voice coil, and the second voice coil cooperates with the second magnetic portion and the third magnetic portion to drive the second diaphragm assembly to vibrate.