Loudspeaker Apparatus Single Membrane Phase Coherence
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Solution Overview
Problem
Existing loudspeaker systems in vehicles often result in the midrange driver and tweeter being perceived as two separate audio sources due to phase relationship issues caused by their positioning and frequency wavelength differences.
Innovation Solution
A loudspeaker apparatus that uses a single membrane/diaphragm element for generating sound waves in both midrange and high frequency ranges, utilizing a voice coil/magnet assembly for pistonic movement and a piezoelectric layer for modal radiation, thereby eliminating the need for separate drivers and improving phase coherence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate midrange driver and tweeter are used, then frequency coverage is improved, but phase coherence deteriorates causing perception as two independent audio sources
Solution Approach 1:
The patent merges the midrange driver and tweeter into a single integrated loudspeaker apparatus with one common membrane. The voice coil assembly drives the membrane for midrange frequencies while the piezoelectric element vibrates the same membrane for high frequencies, ensuring both frequency ranges originate from a single acoustic source maintaining phase coherence.
Solution Approach 2:
The membrane serves multiple functions: it acts as the radiating surface for both the voice coil-driven midrange frequencies and the piezoelectric-driven high frequencies. This multi-functional design allows a single component to handle different frequency ranges that would traditionally require separate drivers.
2Adaptability or versatility
If multiple loudspeakers are used to cover different frequency ranges, then audio performance is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple driver functions into a single loudspeaker unit. The apparatus integrates a voice coil assembly, a piezoelectric element, and a common membrane into one unified structure, replacing what would traditionally require separate midrange and tweeter loudspeakers.
Solution Approach 2:
The single loudspeaker apparatus performs multiple functions: the voice coil assembly handles midrange frequencies while the piezoelectric element handles high frequencies, both using the same membrane. This multi-functional design reduces the total number of loudspeaker units needed in the audio system.
3Reliability
If midrange driver and tweeter are positioned close together, then phase relationship is improved, but mounting flexibility deteriorates
Solution Approach 1:
By merging the midrange and tweeter functions into a single mounted unit with a common membrane, the patent eliminates the need to carefully position separate drivers close together. The single apparatus maintains perfect phase relationship while providing standard mounting flexibility.
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 configuration provides an exceptionally wide operating range, covering frequencies from 200 Hz to 24 kHz, and ensures synchronized sound reproduction from a single source, reducing the number of required loudspeakers and enhancing acoustic performance.
Implementation Method 1
a voice coil (14) arranged to immerse in a magnet field (15) of a magnet element (15), the voice coil (14) driving the membrane element (12) back-and-forth
Implementation Method 2
a piezoelectric layer (17) formed as a composite structure... the at least one piezoelectric layer or element (17) causing the membrane element (12) to vibrate
Data Source
Figure 1
Figure 2~3
AI summary
Loudspeaker apparatus (10) for emitting high and low frequency sound waves, comprising: at least one membrane element (12) for generating sound waves, said membrane element (12) being adapted to simultaneously generate sound waves in a first frequency range and in a second frequency range; at least one voice coil/magnet assembly (14, 15) adapted for operatively engaging with the membrane element (12) such that the membrane element (12) is drivable by the voice coil/magnet assembly (14, 15) in the first frequency range to generate sound waves in the first frequency range; and at least one piezoelectric layer or element (17) being arranged at the membrane element (12) in such a way that the membrane element (12) is drivable by the piezoelectric layer or element (17) in the second frequency range in order to generate sound waves in the second frequency range.