Loudspeaker Suspension Element with Localized Stiffness Profiles
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Solution Overview
Problem
Loudspeaker drivers with progressive suspension elements often suffer from non-linear stiffness, leading to distortion and damage during large excursions, especially when the diaphragm geometry includes both curved and straight sections, resulting in uneven force distribution and standing wave resonance issues.
Innovation Solution
A novel suspension element with two opposing straight sections and two opposing curved sections, where the curvature radius of the curved sections is smaller than that of the straight sections, and the mean height of the radial cross-sectional profile of the curved sections is higher, providing a more idealized stiffness profile with linear motion for small displacements and rapidly increasing stiffness for large displacements, while redistributing restoring forces to reduce standing wave resonance patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a progressive suspension element with round shape and uniform cross-sectional profile is used, then the suspension provides fairly constant stiffness for small displacements and rapidly increasing stiffness for large displacements, but the force distribution becomes uneven when the diaphragm has straight sections joined by curves, resulting in non-linear stiffness and distortion
Solution Approach 1:
The suspension element applies different cross-sectional profiles to different sections: straight sections have a first cross-sectional profile while curved sections have a second cross-sectional profile. This local differentiation allows the straight sections to provide consistent linear stiffness while the curved sections accommodate the geometric transitions, resolving the non-linear stiffness problem and reducing distortion while maintaining driver protection.
2Stability of the object's composition
If the suspension element has a round shape with axial-symmetry, then the force exerted by the suspension element is equal and symmetrical at all locations, but the stiffness profile becomes non-linear when the diaphragm geometry includes straight and curved sections
Solution Approach 1:
The suspension element differentiates between straight and curved sections by assigning different cross-sectional profiles to each. Straight sections use a profile optimized for linear motion and symmetrical force distribution, while curved sections use a profile that accommodates geometric transitions. This local optimization maintains overall stability while achieving precise linear motion characteristics.
3Adaptability or versatility
If the suspension element uses a stadium shape with closed profile straight sections and open profile curved sections, then the geometry accommodates the diaphragm shape, but the stiffness profile becomes very non-linear and the progressive suspension fails to function properly
Solution Approach 1:
The suspension element maintains the stadium shape to accommodate the diaphragm geometry, but applies different cross-sectional profiles to different sections. Straight sections have a first cross-sectional profile that ensures proper progressive suspension characteristics, while curved sections have a second profile that accommodates the geometric transitions. This local differentiation preserves both geometric adaptability and progressive suspension functionality.
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 reduces distortion for small displacements, provides proper driver protection, and increases the linear excursion range, while also raising the upper frequency limit for sound reproduction by minimizing standing wave patterns, resulting in improved sound quality and reduced coloration.
Implementation Method 1
a suspension element surrounding the diaphragm and elastically coupling it to the chassis
Implementation Method 2
a vibrating diaphragm, which is driven axially by means of electromagnetic induction forces generated by alternating current
Data Source
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AI summary
The present invention providesa loudspeaker driver not suffering from high levels of distortion caused by the non-linear stiffness commonly found with drivers that utilize progressive suspension elements. The novel suspension element (100) for suspending the diaphragm (300) of a loudspeaker driver to the chassis (400) thereof has a geometry with two opposing first sections (130) and two opposing second sections (110), which connect the two first sections (130). The second sections 1 have a curvature radius smaller than that of the first sections 10 30. The mean height of the radial cross-sectional profile of the second section (110) is higher than the height of the cross- sectional profile of the first sections (130). The first sections (130) have an axial stiffness greater than the second sections (110).