Flat Loudspeaker Membrane Resonance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional acoustic devices, including cone and dome speakers, suffer from phase shift and inconsistency due to the volume of air masses required for operation, leading to parasitic harmonics and distortion in sound reproduction, especially when deviating from the tuned frequency.
Innovation Solution
A flat loudspeaker design featuring a resonant excitation membrane with a specific aspect ratio, honeycomb structure, and non-uniform stiffness, attached to a support frame using foam tape, and equipped with strategically placed electrodynamic vibration exciters, optimized to distribute resonant modulations uniformly across the membrane for improved sound quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air-filled enclosure is used to invert phase from the back of the speaker, then phase matching between front and back is improved, but phase modulations and parasitic harmonics occur when deviating from tuning frequency
Solution Approach 1:
The invention removes the air-filled enclosure entirely, extracting the problematic component that caused phase modulations and parasitic harmonics. The phase inversion function is achieved through the bipole configuration of the resonating membrane itself, eliminating the need for enclosures and the associated harmful effects.
Solution Approach 2:
Instead of using an enclosure to invert phase from the back, the invention inverts the approach by using a resonating membrane that naturally produces bipole audio signals with phase inversion inherent to its resonant operation. The membrane vibrates in-phase in both directions from the membrane surface, achieving phase matching without enclosures.
2Power
If conventional cone or dome speakers are used, then acoustic output is achieved, but volume of air masses is required leading to phase shift and inconsistency
Solution Approach 1:
The invention extracts and eliminates the requirement for large volumes of air masses by using a resonating membrane that operates with minimal air displacement. The membrane's resonant vibration generates acoustic output without needing the substantial air volumes required by conventional cone or dome speakers.
Solution Approach 2:
The invention changes the operational parameters from conventional speaker designs that require large air masses to a resonating membrane system that operates with minimal air displacement. The membrane's physical parameters (width to height ratio, attachment points, material properties) are optimized to achieve acoustic output through resonant vibration rather than air mass movement.
3Reliability
If multiple design features are changed to improve sound quality, then acoustic performance may be improved, but it is impossible to change one parameter without affecting others
Solution Approach 1:
The invention segments the design into distinct, independently optimized parameters: membrane width-to-height ratio, exciter attachment points, membrane material properties, and frame design. Each parameter can be adjusted and optimized separately while maintaining overall system performance, reducing the interdependence complexity.
Solution Approach 2:
The invention applies local quality by optimizing specific regions and parameters independently - such as the membrane's width-to-height ratio, the specific attachment points of exciters, and local material properties - allowing each parameter to be tuned for its specific function without requiring changes to all other parameters.
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 solution achieves a significant improvement in sound reproduction quality by minimizing phase shifts, reducing harmonic distortions, and ensuring a wide frequency range with minimal labor and material costs, allowing for the generation of the entire audible sound spectrum with reduced harmonic distortion.
Implementation Method 1
equipped with strategically placed electrodynamic vibration exciters
Implementation Method 2
A flat loudspeaker design featuring a resonant excitation membrane with a specific aspect ratio
Implementation Method 3
the member having certain physical parameters the values of which affect the distribution of resonant modes of bending wave vibration over the active area of the member
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The flat loudspeaker including an enclosure in the form of a support frame, a sound-emitting rectangular membrane attached to the frame, and an electrodynamic vibration exciter located opposite the membrane. Besides, the vibration exciter is attached with one of its ends to the membrane within a special line passing along the plane of the rectangular membrane, emerging from any vertex of the rectangular membrane, and ending at a point on the opposite vertex of the membrane's horizontal side located at a distance of 2/3 of the membrane's opposite side from the top horizontally.