Multipoint Adaptive Equalization for Car Cabin Audio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multipoint adaptive equalization systems in car cabins suffer from deteriorated sound characteristics at control points other than the main point, leading to a feeling of strangeness in hearing due to average compensation of frequency-phase characteristics, and require multiple speakers and microphones, increasing circuit complexity and calculation.
Innovation Solution
Applying an inverse phase characteristic opposite to the phase characteristic from a speaker to a main control point, and using adaptive signal processing to minimize the sum of error signal powers, thereby determining a gain for the audio signal and improving sound characteristics in multiple control points with only one speaker and one adaptive signal processor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple speakers and microphones are used for multipoint adaptive equalization control, then sound characteristics at multiple control points can be improved, but device complexity and calculation amount increase
Solution Approach 1:
The patent merges multiple control functions into a single adaptive signal processor by using multiple microphones to capture sound fields at different control points and processing them collectively. This allows multipoint equalization control to be achieved with one speaker and one adaptive signal processor, reducing device complexity while maintaining sound quality at multiple points
Solution Approach 2:
The single adaptive signal processor is designed to handle multiple control points simultaneously, making it a multi-functional device that can service the entire acoustic space. The system uses multiple microphones feeding into one processor, which universally manages equalization for all control points rather than requiring dedicated processors for each point
2Manufacturing precision
If average compensation of frequency-phase characteristics is applied to multiple control points, then sound characteristics at non-main points improve, but a feeling of strangeness in hearing occurs at the main control point
Solution Approach 1:
The patent applies different processing strategies to different control points: the main control point receives precise phase and frequency compensation to maintain natural hearing, while other control points receive gain optimization. This local differentiation ensures the main point maintains hearing naturalness while other points achieve acceptable sound quality
Solution Approach 2:
The system uses multiple microphones to provide feedback about the actual sound field at each control point, allowing the adaptive signal processor to continuously adjust and optimize the output. This feedback mechanism enables the system to maintain natural hearing at the main point while improving sound characteristics at other points through iterative optimization
Data Source
Figure 1
Figure 2A~3B
Figure 4A~5B
AI summary
Provided are a multipoint adaptive equalization control method and system for performing adaptive equalization control on sound detected at a plurality of control points in a car cabin. An inverse phase characteristic opposite to a phase characteristic from a speaker to a main control point is applied to an audio signal output from an audio source. Error signals respectively indicating the differences between detection signals, corresponding to a detected sound signal output from the speaker, in the respective control points and target signals for the control points are output. A gain of an audio signal is determined by performing adaptive signal processing so that the sum of powers of the input error signals is minimized. The inverse phase characteristic and the gain are applied to an audio signal and the resultant audio signal is supplied to the speaker.