Array Speaker Radiation Pattern Cancellation
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Solution Overview
Problem
Array speaker systems experience non-uniform radiation patterns at short distances, leading to distorted sound quality due to insufficient interference of sound source signals, known as the near field effect, which affects the directivity and sound field formation.
Innovation Solution
A method and apparatus that predict radiation patterns, generate cancellation signals for non-uniform regions, and synthesize these signals with input signals to cancel out distortions, ensuring proper directivity and sound field formation by outputting the synthesized signals to the array speaker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sound source signals are output to array speakers to achieve directivity, then sound can be focused at a specific location, but non-uniform radiation patterns occur at short distances causing distorted sound quality
Solution Approach 1:
The patent applies preliminary anti-action by generating cancellation signals in advance that are specifically designed to counteract the non-uniform radiation patterns. These cancellation signals are created before the main sound output and are combined with the original signals to pre-compensate for the expected distortion, thereby eliminating the harmful near-field effects before they can degrade sound quality
Solution Approach 2:
The patent converts the harmful non-uniform radiation patterns into a benefit by analyzing the predicted radiation patterns and generating corresponding cancellation signals. The system takes the inevitable near-field effect and transforms it into a controlled parameter, using the predicted distortion information to create compensating signals that improve overall sound field uniformity
2Power
If multiple speakers are used to achieve directivity, then sound intensity is increased in a predetermined direction, but interference of sound source signals is insufficient at short distances
Solution Approach 1:
The patent implements feedback by using the predicted radiation patterns as feedback information to adjust and optimize the cancellation signals. The system continuously monitors the expected sound field distribution and uses this feedback to refine the cancellation signal generation, ensuring that the interference effects are properly controlled even at short distances where multiple speakers are deployed
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 cancels non-uniform radiation patterns, enhancing sound quality by maintaining directivity and reducing the near field effect, particularly in compact devices where users are close to the speaker, allowing for a clear and focused personal sound zone.
Implementation Method 1
the plurality of sound signals are overlapped using a phase difference between the plurality of sound source signals so that intensities of the sound source signals are increased in a predetermined direction
Implementation Method 2
generating cancellation signals with respect to at least one region corresponding to non-uniform radiation patterns of the predicted radiation patterns
Data Source
AI summary
An array speaker system canceling non-uniform radiation patterns and a method for implementing the same are provided. The method for canceling non-uniform radiation patterns includes predicting radiation patterns in an array speaker with respect to input signals, generating cancellation signals with respect to at least one region corresponding to non-uniform radiation patterns of the predicted radiation patterns, synthesizing the input signals and the cancellation signals, and outputting the synthesized signals to the array speaker. Sound signals from which non-uniform radiation patterns having distorted sound are cancelled such that a stable sound field having uniform radiation characteristics may be obtained and provided to a listener.