Speaker Excursion Feedback for Multiband Bass Gain Control

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Solution Overview

Problem

Conventional sound producing systems face limitations in optimizing sound quality and loudness, particularly in audible bass bands, due to restricted gain range and limited improvement in low frequency bands, leading to suboptimal performance.

Innovation Solution

A sound producing system that estimates speaker excursion using feedback current and voltage to adjust amplification gain and employs multi-band dynamic range control (MBDRAC) to optimize audio signal processing across different frequency bands, ensuring improved sound quality and loudness based on the speaker's capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the gain of the amplifying apparatus is automatically controlled according to the excursion of the speaker, then the speaker protection is improved, but the improvement space for low frequency band of the audio is limited

Engineering Contradiction:
Improvespeaker protectionVSAvoidlow frequency band improvement space
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent divides the audio signal into multiple frequency bands (low frequency band, mid frequency band, high frequency band) and applies different gain control strategies to each band. The low frequency band gain is controlled based on speaker excursion characteristics, while other bands use different control methods, allowing optimized protection and performance for each frequency range independently

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic gain adjustment where the gain for low frequency band is continuously adapted based on real-time speaker excursion measurements. The system dynamically determines the maximum allowable gain based on current excursion conditions, enabling the gain to vary over time to both protect the speaker and maximize audio output within safe limits

Inventive Principle:
Principle #15Dynamics

2Reliability

If the range of the gain for amplifying the audio is limited, then the speaker excursion is controlled, but the sound quality and loudness optimization is restricted

Engineering Contradiction:
Improvespeaker excursion controlVSAvoidsound quality and loudness optimization
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies different quality control strategies to different frequency bands. The low frequency band gain is specifically controlled based on speaker excursion to protect the speaker, while other frequency bands are allowed greater gain range for optimized sound quality and loudness. This localized approach allows each band to have optimal characteristics without compromising the other

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the gain parameter dynamically based on speaker excursion conditions. By monitoring excursion and adjusting the gain parameter in real-time, the system maintains speaker protection while enabling sound quality optimization through adaptive parameter adjustment rather than fixed limitations

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2899883B1Sound producing system and audio amplifying method thereof
Publication Date: 2016.07.20 HTC CORP
  • EP2899883B1 patent drawingFigure 1A
  • EP2899883B1 patent drawingFigure 1B
  • EP2899883B1 patent drawingFigure 2

AI summary

The invention provides one sound producing system including a speaker, a driving circuit and an audio controller. The speaker is used for producing an audible sound. The driving circuit is connected to the speaker. The audio controller is configured to receive an input audio signal and pre-amplify the input audio signal with an amplify gain to obtain a pre-amplified audio signal; operate a multiband dynamic range control on the pre-amplified audio signal to obtain an output audio signal; convert the output audio signal to a driving voltage; provide the driving voltage to the speaker through the driving circuit; detect over the driving circuit to obtain at least one excursion parameter to determine an estimated excursion of the speaker in response to the driving voltage; and adjust the amplify gain according to the estimated excursion.