Audio Processor Phase Shift Destructive Interference

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Dual voice coil loudspeakers face challenges in efficiently managing the phase difference between audio signals supplied to each voice coil, leading to undesirable acoustic outputs and power dissipation, particularly in applications requiring stereo signals and self-heating.

Innovation Solution

An audio processor is designed with phase shifters and mixers to adjust the phase difference between audio signals for dual voice coil loudspeakers, allowing for destructive interference and reduced acoustic output while maintaining power dissipation for self-heating or characteristic determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If phase difference between audio signals is not adjusted, then acoustic output is strong, but power dissipation is excessive and causes interference with other devices and animals

Engineering Contradiction:

Improvepower dissipationVSAvoidinterference with other devices and animals

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent applies destructive interference to convert excessive power dissipation and acoustic interference into a beneficial effect. By introducing a phase shift of approximately 180 degrees between signals to the two voice coils, the acoustic outputs cancel each other out, achieving attenuation while the power is still dissipated as heat for self-heating purposes. This transforms the harmful acoustic interference into a useful self-heating mechanism without causing external interference.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If phase shifters and mixers are added to adjust phase difference, then acoustic output is attenuated and self-heating is enabled, but device complexity increases

Engineering Contradiction:

Improveacoustic interferenceVSAvoidaudio processor complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The audio processor is designed to perform multiple functions: it can adjust phase difference for destructive interference to attenuate acoustic output, enable self-heating by dissipating power, and determine transducer characteristics through impedance measurement. The phase shifter and mixer components serve these multiple purposes, allowing a single device to handle both audio processing and diagnostic functions without requiring separate systems.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the phase parameter of audio signals introduced to the voice coils. By adjusting the phase shift to approximately 180 degrees, the system achieves destructive interference for acoustic attenuation. The audio processor dynamically modifies this phase parameter to control the degree of attenuation and enable different operating modes including self-heating and characteristic determination.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If dual voice coil configuration is used for stereo signals, then single speaker can output stereo signals, but phase management becomes complex and acoustic interference occurs

Engineering Contradiction:

Improvestereo signal capabilityVSAvoidphase management complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The audio processor acts as an intermediary between the audio source and the dual voice coil speaker. It introduces phase shifters and mixers that manage the phase relationships between signals to the two voice coils, enabling stereo signal output while controlling acoustic interference. The intermediary device handles the complex phase management, allowing the speaker itself to remain relatively simple while achieving versatile stereo capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution effectively attenuates acoustic output and allows for self-heating of loudspeakers, improving performance by dissipating power without interference with other devices or animals, and enables accurate determination of transducer characteristics.

Implementation Method 1

adjusting a phase difference between a first audio signal and a second audio signal to a value that causes the first audio signal and the second audio signal to interfere destructively when supplied to the first voice coil and the second voice coil, respectively

Methodology Applied

Scientific EffectDestructive interference: Interference

Implementation Method 2

maintaining power dissipation for self-heating

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS10779086B2Audio processor

Publication Date: 2020.09.15 GOODIX TECH HK CO LTD

AI summary

An audio processor for a multi voice coil acoustic transducer is described. The audio processor may receive or generate an audio signal. The audio signal may have one or more phase shifts applied. The audio signal may be used to drive a first coil of a dual voice coil acoustic transducer. The phase-shifted audio signals may drive the other coils of a multi voice-coil acoustic transducer. The phase shift is selected so that the phase difference between the audio signal driving each voice coil may result in destructive interference in the multi voice-coil loudspeaker resulting in reduced or no acoustic output due to the audio signal.