Dual-Speaker Earphone Crossover to Reduce Diaphragm Distortion
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Solution Overview
Problem
Existing earphones using single-channel electrical signal driving for speakers with different frequency bands face diaphragm distortion due to excessive amplitude, compromising sound quality and user experience.
Innovation Solution
An earphone design with a high-pass frequency divider between speakers, setting the frequency-dividing point above 6 kHz, and a driving circuit that simultaneously drives two speakers via a digital-to-analog conversion circuit, ensuring sound pressure level attenuation of at least 20 dB for one speaker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-channel electrical signal driving is used for speakers with different frequency bands, then device complexity is reduced, but diaphragm distortion occurs due to excessive amplitude
Solution Approach 1:
The patent divides the frequency spectrum into different bands using frequency dividers (high-pass and low-pass filters) to separate signals for different speakers. This segmentation allows each speaker to receive only the frequency range it is designed for, preventing diaphragm distortion while maintaining relatively simple circuit architecture.
Solution Approach 2:
The patent changes the electrical signal parameters by introducing frequency division with specific cutoff frequencies (e.g., 6kHz, 9kHz) and attenuation levels (e.g., 20dB, 30dB). This parameter modification ensures that each speaker receives appropriately filtered signals, resolving the distortion issue without requiring completely different driving approaches.
2Reliability
If frequency division is applied to separate frequency bands for different speakers, then sound quality is improved, but device complexity increases
Solution Approach 1:
The patent implements segmentation of the audio signal into different frequency bands using simple RC filter circuits. The high-pass frequency divider separates high frequencies for the second speaker, while the low-pass frequency divider handles low frequencies for the first speaker, achieving frequency separation with minimal circuit complexity.
Solution Approach 2:
The patent introduces frequency dividers as intermediary components between the audio source and the speakers. These intermediaries (high-pass and low-pass filters) mediate the signal transmission, ensuring each speaker receives appropriately filtered signals without requiring complex multi-channel amplification systems.
3Reliability
If a high-pass frequency divider with frequency-dividing point not lower than 6 kHz is used, then diaphragm distortion is reduced, but sound pressure level attenuation increases
Solution Approach 1:
The patent carefully selects and adjusts the frequency-dividing point parameter of the high-pass filter (set at not lower than 6kHz) and the attenuation level (not less than 20dB). By optimizing these parameters, the patent achieves sufficient distortion reduction while minimizing unnecessary energy loss in the audible frequency range.
Solution Approach 2:
The patent applies partial frequency division by using a high-pass filter with a relatively high cutoff frequency (≥6kHz) rather than dividing the entire spectrum. This partial action approach targets only the high-frequency range where the second speaker operates, reducing distortion without excessively attenuating other important frequency components.
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
Improves sound quality by reducing diaphragm distortion and enhancing auditory experience through targeted frequency division and simultaneous speaker driving.
Implementation Method 1
a high-pass frequency divider disposed between the driving circuit and the second speaker and configured to perform frequency division on an audio driving signal provided by the driving circuit to the second speaker
Data Source
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AI summary
The present disclosure relates to an earphone. The earphone includes a first speaker, a second speaker, and a driving circuit. The driving circuit is configured to drive the first speaker and the second speaker, at least a portion of a frequency band of sound output by the first speaker is lower than a frequency band of sound output by the second speaker. The earphone further includes a high-pass frequency divider disposed between the driving circuit and the second speaker and configured to perform frequency division on an audio driving signal provided by the driving circuit to the second speaker, and a frequency-dividing point of the high-pass frequency divider is set to be not lower than 6 kHz.