Speaker Overheating Control Using Infrasonic Cooling Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for suppressing speaker overheating either fail to quickly cool the speaker or significantly reduce audio quality, leading to user discomfort.
Innovation Solution
An audio system that includes an overheating detector, a cooling processing section, and a controller to switch between audio signals, using a cooling signal at infrasonic frequencies to vibrate the speaker's vibration plate at a larger amplitude, generating greater airflow for cooling while maintaining audible audio quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the level of audio signal to be output to the speaker is reduced when temperature rise is excessive, then heat generation in the speaker is suppressed, but the sound volume heard by the user is low and user comfort is degraded
Solution Approach 1:
The patent extracts only the low-frequency component from the audio signal and removes it during overheating conditions. This selective removal allows the system to reduce heat generation by eliminating the primary heat-producing frequency range while preserving other frequency components that contribute to audio quality and user listening experience.
Solution Approach 2:
The patent changes the frequency parameter of the audio signal by removing the low-frequency component. This parameter change enables the system to reduce heat generation (since low frequencies produce more heat) while maintaining audio playback functionality and user comfort through the remaining frequency components.
2Measurement precision
If a sensor that detects vibration of a vibration plate is provided, then vibration detection is enabled, but the speaker is more prone to overheating which can damage the sensor and attached devices
Solution Approach 1:
The patent applies preliminary anti-action by proactively removing the low-frequency component from the audio signal before it can cause excessive heat generation. This preventive measure protects the vibration detection sensor and attached devices from overheating damage while allowing the sensor to continue functioning for vibration detection purposes.
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
Quickly cools the overheated speaker without significantly affecting user listening experience by using infrasonic frequencies to enhance airflow and reduce nonlinear distortion.
Implementation Method 1
a signal obtained by mixing a signal obtained by removing a low-frequency component from the first audio signal output by the audio source device with a cooling signal at an infrasonic frequency lower than an audible frequency range
Implementation Method 2
it is possible to vibrate the vibration plate of the speaker at an amplitude larger than that when the first audio signal is output to the speaker. Therefore, it is possible to generate greater air flow in the speaker and more powerfully and quickly cool the speaker by the air flow
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
In an audio system, when overheating of a speaker is detected, a controller controls first and second selectors to input an audio signal output by an audio source device to a cooling processing section and cause output of the cooling processing section to be output to the speaker. In the cooling processing section, a mixer mixes an audio signal obtained by removing a low-frequency component from the input audio signal by a high-pass filter with a cooling signal at an infrasonic frequency generated by a cooling signal generator and adjusted with a gain by a gain adjuster. An audio signal obtained by mixing the audio signal with the cooling signal is output from the cooling processing section via a nonlinear inverse filter. A gain setting section sets the gain such that power of the cooling signal matches power of the low-frequency component extracted by a low-pass filter.