Speaker Acoustic Paths with Impedance Segmentation

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Solution Overview

Problem

Conventional magnetic fluid speakers face challenges in reproducing high-frequency sounds due to resonance and standing wave issues, which degrade sound quality and require additional components, increasing costs.

Innovation Solution

The speaker design incorporates multiple acoustic paths with varying acoustic impedance and strategically placed dampers on sound conduit tubes to reduce resonance peaks and maintain low-frequency sound pressure characteristics, allowing for improved reproduction of low-pitched sounds with flat frequency characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple acoustic paths with different acoustic impedances are introduced, then resonance peaks are reduced and low-frequency sound pressure characteristics are maintained, but device complexity increases

Engineering Contradiction:

Improvesound qualityVSAvoidacoustic path configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The acoustic path is segmented into multiple parallel paths (first acoustic path and second acoustic path) with different acoustic impedances. This segmentation allows different frequency ranges to be handled by different paths, reducing resonance peaks while maintaining low-frequency characteristics, thus resolving the contradiction between sound quality and path complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each acoustic path is assigned different local quality characteristics through varying acoustic impedance. The first acoustic path has higher acoustic impedance while the second has lower acoustic impedance, allowing each path to optimally handle specific frequency ranges, thereby improving overall sound quality without requiring excessive complexity.

Inventive Principle:

Principle #3Local quality

2Reliability

If dampers are added to sound conduit tubes, then resonance peaks are reduced, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveresonance controlVSAvoiddamper configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The harmful resonance phenomenon is extracted and targeted specifically through selective damper placement. Instead of adding dampers throughout the system, dampers are strategically placed only in specific sound conduit tubes where resonance occurs, effectively reducing resonance peaks while minimizing the increase in device complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Dampers serve as intermediary elements introduced into specific acoustic paths to mediate the resonance problem. These dampers absorb excess acoustic energy at resonance frequencies without significantly affecting the overall acoustic performance or requiring major structural modifications.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If acoustic paths are formed in the magnetic circuit, then low-frequency sound reproduction is improved, but the magnetic circuit design becomes more complex

Engineering Contradiction:

Improvelow-frequency sound reproductionVSAvoidmagnetic circuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The magnetic circuit is designed to serve multiple functions: it provides magnetic flux conduction for voice coil operation and simultaneously forms acoustic paths for sound reproduction. By making the magnetic circuit multi-functional, low-frequency sound reproduction is improved without requiring separate acoustic structures, thus minimizing the increase in overall device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The acoustic paths are merged with the magnetic circuit structure rather than being separate components. The magnetic circuit components (yoke, magnet, pole pieces) are configured to also serve as acoustic conduits, combining magnetic and acoustic functions into a single integrated structure, thereby improving low-frequency reproduction while avoiding additional complexity.

Inventive Principle:

Principle #5Merging (Combining)

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 effectively curbs resonance peaks without degrading low-frequency sound pressure characteristics, enabling the speaker to produce high-quality low-pitched sounds with improved frequency consistency.

Implementation Method 1

the plurality of acoustic paths include a first acoustic path and a second acoustic path that differs in acoustic impedance from the first acoustic path

Methodology Applied

Scientific EffectAcoustic impedance: Acoustics

Implementation Method 2

a magnetic circuit, a plurality of acoustic paths that provide connection between a space formed on a side including the magnetic circuit with respect to the diaphragm

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentUS9432773B2Speaker and audio-visual system

Publication Date: 2016.08.30 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A speaker includes a diaphragm and a magnetic circuit, a plurality of acoustic paths that provide connection between a space formed on a side including the magnetic circuit with respect to the diaphragm and a space exterior to the speaker are formed in the magnetic circuit, and the plurality of acoustic paths include a first acoustic path and a second acoustic path that differs in acoustic impedance from the first acoustic path.