Speaker Module Sound-Absorbing Cotton High-Frequency Sensitivity

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Solution Overview

Problem

The existing speaker modules with lateral side sound emission structures suffer from a deep valley in sensitivity at high frequencies due to standing waves forming in the front acoustic cavity, leading to reduced sound pressure amplitude and acoustic performance.

Innovation Solution

Incorporating sound-absorbing cotton in the front acoustic cavity, positioned between the speaker unit and the cavity's reflecting surface, to lengthen the sound wave propagation distance and avoid standing wave formation, thereby improving high-frequency sensitivity without modifying the cavity structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If sound is emitted from the lateral side of the front cavity, then the speaker module achieves a compact structure, but standing waves form in the front acoustic cavity causing deep valleys in sensitivity at high frequencies

Engineering Contradiction:

Improvemodule structureVSAvoidacoustic performance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Sound-absorbing cotton is introduced as an intermediary material in the front acoustic cavity to absorb reflected sound waves and prevent standing wave formation. This mediator resolves the contradiction by eliminating the harmful acoustic interference while preserving the compact lateral emission structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Porous sound-absorbing cotton is used to fill the front acoustic cavity, utilizing its porous structure to absorb high-frequency sound waves and prevent standing wave formation, thereby improving acoustic performance without compromising the compact design

Inventive Principle:

Principle #31Porous materials

2Reliability

If sound-absorbing cotton is added to the front acoustic cavity, then high-frequency sensitivity is improved, but device complexity increases

Engineering Contradiction:

Improvehigh-frequency sensitivityVSAvoidcavity structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

Sound-absorbing cotton is used as a simple, inexpensive material that can be easily installed and replaced if needed, providing an cost-effective solution to improve high-frequency sensitivity without requiring complex structural modifications

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 arrangement of sound-absorbing cotton effectively enhances the sensitivity curve at high frequencies, improving acoustic performance by preventing standing wave interference, while maintaining a simple and compact module design.

Implementation Method 1

a sound-absorbing cotton is arranged in the front acoustic cavity, the sound-absorbing cotton is fixed on the module housing

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentUS10158937B2Speaker module

Publication Date: 2018.12.18 GOERTEK INC

AI summary

A speaker module comprising a module housing is disclosed. A speaker unit is accommodated within the module housing. A sound hole of the module is located at a side of the speaker unit. The speaker unit divides a cavity of the entire module into two cavities, namely a front acoustic cavity and a rear acoustic cavity. The front acoustic cavity is in communication with the sound hole. A sound-absorbing cotton is provided in the front acoustic cavity. The sound-absorbing cotton is fixed on the module housing, and is arranged to avoid a vibration space of a diaphragm of the speaker unit. The present invention effectively improves the performance of a sensitivity curve of the module at high frequencies without modifying the structure of the front acoustic cavity, thus not only increasing the acoustic performance of the module, but also simplifying the structure of the front acoustic cavity of the module.