Speaker Module Porous Grains Low-Frequency Performance

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Solution Overview

Problem

Traditional closed speaker boxes face inferior low-frequency performance due to sound wave reflections interfering with diaphragm vibrations, which is exacerbated by the size constraints of portable electronic devices.

Innovation Solution

Incorporating porous grains within the speaker box to absorb air vibrational energy, converting it into heat energy and reducing the impact of sound wave reflections, thereby enhancing low-frequency performance without increasing the speaker box volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the volume of the speaker box is increased to reduce sound wave reflection pressure, then low frequency performance is improved, but the device size increases which is not suitable for portable electronic products

Engineering Contradiction:
Improvelow frequency performanceVSAvoidspeaker box volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent introduces porous grains (such as porous ceramic beads or porous polymer beads) into the speaker box cavity. These porous materials absorb sound wave energy through friction and viscous losses within their pore structures, reducing the harmful pressure buildup from sound wave reflections without requiring increased box volume. The porous grains effectively dissipate acoustic energy while maintaining a compact speaker box design suitable for portable devices.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The porous grains act as an intermediary substance between the sound waves and the air in the speaker box. They mediate the interaction by absorbing excess acoustic energy and reducing the intensity of reflected sound waves, thereby improving low frequency performance without directly modifying the box volume or diaphragm structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of stationary object

If the volume of the speaker box is kept small for portable devices, then arrangement space is saved, but low frequency performance deteriorates due to sound wave reflection pressure

Engineering Contradiction:
Improvespeaker box volumeVSAvoidlow frequency performance
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

By incorporating porous grains into the limited space of a compact speaker box, the patent enables effective absorption of sound wave energy without increasing the overall volume. The porous structure provides a large surface area within a small volume, maximizing acoustic energy dissipation while maintaining the compact form factor required for portable electronic products.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent changes the physical parameters of the air in the speaker box by introducing porous materials that alter the acoustic impedance and energy dissipation characteristics. This parameter change allows the small speaker box to achieve better low frequency performance by modifying how sound waves interact with the air molecules through the porous grain structure.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If porous grains are added to absorb sound wave energy, then low frequency performance is improved, but the device complexity increases

Engineering Contradiction:
Improvelow frequency performanceVSAvoidspeaker module complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses commercially available porous ceramic or polymer beads as off-the-shelf components that can be easily incorporated into the speaker box. These standardized porous materials require minimal processing or customization, allowing manufacturers to improve low frequency performance without significantly increasing manufacturing complexity or requiring specialized production processes.

Inventive Principle:
Principle #31Porous materials

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 solution effectively enhances low-frequency performance while saving arrangement space, effectively increasing the equivalent volume of the speaker box, suitable for slim electronic products.

Implementation Method 1

When sound waves are transmitted into pores of the porous grains and cause friction, vibrational energy of the air particles is converted into heat energy in the pores

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The porous grains are adapted to absorb energy of air in the speaker box

Methodology Applied
Scientific EffectEnergy absorption: Absorption (physical)

Data Source

PatentEP3496418B1Speaker module
Publication Date: 2020.09.16 ACER INC
  • EP3496418B1 patent drawingFigure 1~2
  • EP3496418B1 patent drawingFigure 3~4
  • EP3496418B1 patent drawingFigure 5

AI summary

A speaker module including a speaker box, a diaphragm and a plurality of porous grains is provided. The diaphragm is disposed on the speaker box and adapted to receive a signal to vibrate. The porous grains are disposed in the speaker box and adapted to absorb energy of air in the speaker box.