Vehicle Headrest Speaker Layout for Acoustic Privacy
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Solution Overview
Problem
Existing vehicle headrests with integrated speaker modules suffer from limited sound quality and inadequate acoustic privacy due to their small size, which affects sound quality and voice interaction privacy for drivers and passengers.
Innovation Solution
A vehicle headrest design incorporating a speaker module with a housing, diaphragm, and acoustic inverting tube, where sound waves are directed through specific sound holes and a coupling back cavity to enhance sound quality and privacy, utilizing acoustic inverting tubes to optimize sound propagation and reduce passive vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the speaker module size is increased to improve sound quality, then sound quality improves, but the headrest size and complexity increase
Solution Approach 1:
The speaker module is nested within the headrest shell, with the diaphragm integrated into the headrest structure. The acoustic inverting tube is positioned within the speaker module housing, creating a compact nested arrangement that delivers enhanced sound quality without proportionally increasing overall headrest size or structural complexity.
2Manufacturing precision
If the speaker module size is increased to improve sound quality, then sound quality improves, but the headrest becomes larger
Solution Approach 1:
The acoustic inverting tube is positioned specifically at the rear of the speaker module to target low-frequency sound enhancement locally. The diaphragm is integrated at the front facing the user's ear, concentrating sound projection in the desired direction. This localized optimization allows improved sound quality without requiring a proportional increase in overall headrest volume.
3Loss of information
If acoustic isolation is enhanced to improve privacy, then voice interaction privacy improves, but sound propagation may be affected
Solution Approach 1:
The acoustic system is segmented into distinct functional zones: the front sound outlet directed toward the user's ear for private voice interaction, the rear acoustic inverting tube for low-frequency enhancement, and the coupling back cavity connecting them. This segmentation allows sound to be privately delivered to the user while separately managing low-frequency propagation through the acoustic inverting tube, maintaining both privacy and sound quality.
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 design improves sound quality and acoustic privacy by reducing passive vibrations and enhancing low-frequency performance, increasing the dependency between the headrest and the user's ear, and achieving better acoustic isolation.
Implementation Method 1
a speaker unit received in the housing, including a diaphragm configured to vibrate to generate sound wave transmitted to outside through the sound outlet
Implementation Method 2
the acoustic inverting tube is received in the coupling back cavity; the first opening is communicated with the back sound hole; the second opening is communicated with the coupling back cavity; sound wave emitted from the back sound hole has a first sound phase, sound wave emitted from the sound outlet has a second sound phase, a difference between the first sound phase and the second sound phase is in a range of 2π/3-4π/3
Data Source
AI summary
The present disclosure discloses a vehicle headrest including a main body having a receiving chamber and a first sound hole, and a speaker module including a housing fixed to the main body and including a sound outlet, a speaker unit including a diaphragm, and an acoustic inverting tube. The housing further comprises a back sound hole communicated with the coupling back cavity; the acoustic inverting tube is received in the coupling back cavity. The sound wave output from the back sound hole has a first sound phase, the sound wave output from the sound outlet has a second sound phase, a difference between the first sound phase and the second sound phase is in a range of 2π/3-4π/3. The vehicle headrest in the present disclosure has better sound quality and higher acoustic privacy.