Electroacoustic Transducer Crossover Sound Pressure Dip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electroacoustic transducers comprising dynamic and piezoelectric speakers experience a sudden drop in sound pressure level near the crossover frequency due to the intersection of sound pressure levels from both speakers, leading to suboptimal acoustic properties in earphones and headphones.
Innovation Solution
The transducer design ensures that the sum of sound pressures from the dynamic and piezoelectric speakers in the crossover frequency range is equal to or greater than 0.5 times the sound pressure of the dynamic speaker, achieved by optimizing the size and number of passage parts and adjusting the phases of the reproduced sounds to minimize the dip in sound pressure level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a dynamic speaker and a piezoelectric speaker are used in parallel to cover wide bandwidth, then the frequency range is improved, but a sudden drop in sound pressure level occurs near the crossover frequency
Solution Approach 1:
A passage part is introduced as an intermediary acoustic channel that allows sound waves from the dynamic speaker to reach the rear surface of the piezoelectric speaker's vibration plate. This mediator enables acoustic coupling between the two speakers, allowing the sound waves to superimpose and compensate for the sound pressure drop near the crossover frequency, thereby resolving the contradiction between wide bandwidth and sound pressure stability
Solution Approach 2:
The patent merges the acoustic outputs of the dynamic speaker and piezoelectric speaker by allowing their sound waves to superimpose through the passage part. The sound waves from both speakers combine in the crossover frequency range, creating a composite sound that maintains stable sound pressure levels and eliminates the sudden drop that would occur if the speakers operated independently
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
This approach effectively reduces the sudden drop in sound pressure level near the crossover frequency, enhancing acoustic properties and maintaining a consistent sound pressure level across the frequency range.
Implementation Method 1
a piezoelectric speaker that generates a second acoustic sound
Implementation Method 2
a dynamic speaker that generates a first acoustic sound
Implementation Method 3
The sum of the sound pressures of the first and second acoustic sounds in a crossover frequency range of the sound pressure of the first acoustic sound and the sound pressure of the second acoustic sound, is equal to or greater than 0.5 times the sound pressure of the first acoustic sound in the crossover frequency range
Data Source
AI summary
An electroacoustic transducer includes a dynamic speaker that generates a first acoustic sound, and a piezoelectric speaker that generates a second acoustic sound. The sum of the sound pressures of the first and second acoustic sounds in a crossover frequency range of the sound pressure of the first acoustic sound and the sound pressure of the second acoustic sound, is adjusted to be equal to or greater than 0.5 times the sound pressure of the first acoustic sound in the crossover frequency range so as to improve the acoustic properties in the crossover frequency range.