Speaker Bass Adjustment Across Volume and Audio Source Changes

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Solution Overview

Problem

Small speaker devices often lack richness in low-frequency sound (bass) when switching audio sources, such as from a portable player to a networked server, due to inadequate bass enhancement techniques.

Innovation Solution

A speaker device with an ADC, audio device, DAC, amplifier, and signal processing controller that adjusts low-frequency components based on detected volume levels, using filters like HPF or BEF to maintain bass richness across varying volume settings and audio sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a small speaker device uses bass enhancement techniques with fixed processing, then low-frequency sound richness is improved at certain volume levels, but bass quality deteriorates when volume is lowered or audio source changes

Engineering Contradiction:
Improvebass richnessVSAvoidbass consistency across volume levels and audio sources
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic bass enhancement by making the low-pass filter characteristics adjustable based on detected audio signal properties. The signal processing controller dynamically modifies filter cutoff frequency and Q-factor according to the audio source type and volume level, allowing the bass enhancement to adapt rather than remain fixed. This resolves the contradiction by making the enhancement dynamic rather than static.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes filter parameters (cutoff frequency and Q-factor) based on detected audio characteristics. When an audio source is detected and volume level is determined, the controller adjusts these parameters to optimize bass enhancement for that specific condition. This parameter adaptation allows consistent bass quality across different volume levels and audio sources.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If a speaker device provides bass enhancement processing, then low-frequency sound quality is improved, but device complexity increases

Engineering Contradiction:
Improvebass qualityVSAvoidsignal processing complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent employs feedback mechanisms where the signal processing controller detects audio signal characteristics (volume level, audio source type) and uses this information to adjust filter parameters in real-time. This closed-loop approach optimizes bass enhancement while maintaining manageable complexity through adaptive control rather than overly complex fixed processing.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically detecting audio source characteristics and volume levels, then autonomously modifying filter parameters without requiring manual user intervention. This self-service capability simplifies operation while providing sophisticated bass enhancement adapted to current conditions.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3379847B1Audio device, speaker device, and audio signal processing method
Publication Date: 2021.08.11 YAMAHA CORP
  • EP3379847B1 patent drawingFigure 1
  • EP3379847B1 patent drawingFigure 2~4
  • EP3379847B1 patent drawingFigure 5

AI summary

An audio device 10 includes: a first detector 17 configured to detect a volume of a first audio signal; and a low-frequency component adjuster 40 configured to generate a second audio signal in which a level of a low-frequency component of the first audio signal is adjusted based on the volume detected by the first detector 17.