Diaphragm Surround Rib Section Restoring Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional surround designs for passive radiators and acoustic drivers, with half roll surrounds made of high durometer materials, often suffer from buckling and hoop stresses leading to unstable dynamic responses and harmonic rocking, detrimental to acoustic performance.
Innovation Solution
A surround design featuring a rib section and a membrane section where the membrane is thinner than the rib section, with the rib section contributing more to the restoring force, utilizing elastomer material with a Shore A durometer between 5 to 70, and arranged in a symmetric pattern to minimize membrane contribution and enhance linear force-deflection response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If half roll surrounds made of high durometer materials are used, then the surround provides structural support and linear force-deflection response, but buckling and hoop stresses occur resulting in unstable dynamic response and harmonic rocking
Solution Approach 1:
The surround is divided into multiple functional components: a thin membrane section for support and a separate rib section for restoring force. This segmentation allows each component to be optimized independently - the membrane provides structural support while the rib provides stable restoring force without causing harmonic rocking
Solution Approach 2:
Different sections of the surround have different thicknesses and material properties. The membrane section has small thickness for flexibility and support, while the rib section has larger thickness for structural stability. This local differentiation allows the membrane to contribute to restoring force without causing instability
2Object-generated harmful factors
If the membrane section thickness is reduced to minimize its contribution to restoring force, then harmonic distortions are reduced, but the membrane's structural support capability is compromised
Solution Approach 1:
The surround is segmented into a thin membrane section that provides structural support and a separate rib section that provides restoring force. This allows the membrane to be thin (minimizing harmonic distortions) while still providing adequate support, as the rib compensates for the reduced membrane thickness
Solution Approach 2:
The surround combines different material properties in a composite structure - the membrane uses material optimized for flexibility and support, while the rib uses material optimized for elastic restoring force. This composite approach allows each component to perform its function effectively despite thickness differences
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 design achieves a stable and efficient acoustic wave creation by reducing harmonic distortions and improving dynamic performance through controlled deformation of the rib sections, maintaining a linear force-deflection response and minimizing membrane contribution.
Implementation Method 1
A restoring force returning the diaphragm to a home position is contributed to more due to deformation of the rib section than to deformation of the membrane section
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A surround for supporting a diaphragm used to create acoustic waves includes a rib section extending away from the diaphragm and a membrane section that is supported by the rib section. The membrane section has a thickness in a direction substantially normal to opposing top and bottom surfaces of the membrane section which is substantially thinner than a thickness of the rib section in a direction substantially normal to opposing top and bottom surfaces of the rib section. A restoring force returning the diaphragm to a home position is contributed to more due to deformation of the rib section than to deformation of the membrane section.