Speaker Output Control Using Frequency-Band Distortion Prevention
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Solution Overview
Problem
Vehicle sound systems often produce distorted outputs due to exceeding speaker output levels when multiple channels are used simultaneously, causing discomfort to drivers, especially when warning sounds or alarms are combined with guidance voices, which can exceed the speaker's frequency range.
Innovation Solution
An apparatus and method that monitor and adjust the output signal level by analyzing frequency bands using Fourier transformation, controlling the volume based on priority orders and energy thresholds to prevent distortion, ensuring stable sound output through speakers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple channel sounds are output simultaneously through the speaker, then the sound coverage and information delivery are improved, but the output level exceeds the speaker's maximum capacity causing distortion
Solution Approach 1:
The system performs preliminary analysis of the output signal before it reaches the speaker. The analyzer detects whether the output level exceeds the maximum level and identifies frequency bands with excessive energy in advance, allowing the controller to adjust volumes preemptively to prevent distortion before it occurs.
Solution Approach 2:
Instead of uniformly reducing the volume of all frequency bands, the system applies local quality control by identifying specific frequency bands that exceed energy thresholds and adjusting only those bands. This allows different parts of the sound spectrum to have different volume levels, maintaining overall sound quality while preventing distortion in problematic frequency ranges.
2Loss of information
If warning sounds and guidance voices are combined, then the information delivery is improved, but the combined sound exceeds the speaker's frequency range causing distortion
Solution Approach 1:
The system performs preliminary Fourier transformation on the combined warning sound and guidance voice signals to analyze their frequency composition before output. This allows the controller to identify frequency bands that may exceed the speaker's capacity and adjust volumes in advance, preventing distortion while maintaining complete information delivery.
Solution Approach 2:
The system changes the volume parameter of specific frequency bands based on their energy levels and the speaker's capacity. By dynamically adjusting the volume of different frequency components of the combined warning and guidance signals, the system maintains faithful reproduction of all information while preventing distortion in frequency ranges that would otherwise exceed the speaker's limits.
3Productivity
If the output signal level is increased to improve sound coverage, then the sound output capacity is improved, but the speaker output level is exceeded causing distortion
Solution Approach 1:
The system applies different volume levels to different frequency bands based on their individual energy levels and the speaker's capacity. This local quality control allows the system to maximize sound output in frequency ranges where the speaker has capacity while preventing distortion in frequency bands that would otherwise exceed limits, thereby improving both sound coverage and distortion prevention.
Solution Approach 2:
The system uses feedback by continuously analyzing the output signal's frequency composition and energy levels, then using this information to adjust the volume of specific frequency bands. This closed-loop control ensures that the speaker operates within its capacity while maximizing overall sound output, preventing distortion while maintaining high productivity.
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 stabilizes sound output by prioritizing frequency bands with higher energy levels and adjusting volumes according to set priorities, preventing distortion and ensuring safe and comfortable audio levels for drivers.
Implementation Method 1
An analyzer is configured to monitor whether an output level of the output signal output from the sound processor exceeds a maximum output level of the speaker between the sound processor and the speaker, and to convert the output signal into a signal of a frequency domain to analyze an energy amount for each frequency
Data Source
AI summary
The present disclosure relates to an apparatus and a method for controlling sound output. The apparatus includes a sound processor configured to amplify a sound signal to a certain level to output an output signal to a speaker. An analyzer is configured to monitor whether an output level of the output signal output from the sound processor exceeds a maximum output level of the speaker between the sound processor and the speaker, and to convert the output signal into a signal of a frequency domain to analyze an energy amount for each frequency when the output level of the output signal exceeds the maximum output level of the speaker. A controller is configured to control a volume for the output signal of the corresponding frequency band when a frequency band having the energy amount exceeding the threshold value is detected from the analyzer.