Actuator Modules with Reduced Stiffness Connections
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Solution Overview
Problem
Conventional loudspeakers, particularly panel audio loudspeakers, face challenges in achieving high sound pressure levels due to the mass of the actuator components impeding the movement of the panel, which reduces acoustic output, especially at higher frequencies.
Innovation Solution
The introduction of actuator modules with reduced stiffness connections between the panel and actuator components, such as using a spacer with lower stiffness than the intermediate layer, and a ring of compliant material to minimize the mass influence on the panel's movement, allowing the coil to transfer kinetic energy more effectively to the panel rather than to adjacent massive components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional actuator modules with stiff connections are used, then structural stability is improved, but the mass of actuator components impedes panel movement and reduces acoustic output especially at higher frequencies
Solution Approach 1:
The actuator module is segmented into separate functional components: the coil assembly, magnet assembly, and panel are connected through compliant elements rather than rigid structures. This segmentation allows each component to move more independently, reducing the effective mass that impedes panel movement while maintaining structural integrity through the distributed compliant connections.
Solution Approach 2:
The stiffness parameter of the connections between actuator components and the panel is changed from high (conventional stiff connections) to low (compliant connections). This parameter change reduces the effective mass coupling between the actuator and panel, allowing the panel to move more freely and generate higher acoustic output, particularly at high frequencies where mass impedance is most problematic.
2Strength
If massive actuator components are directly connected to the panel, then structural support is improved, but the mass influence reduces panel velocity and sound pressure level
Solution Approach 1:
Compliant intermediate elements (such as compliant mounts or flexible connections) are introduced as mediators between the massive actuator components and the panel. These intermediaries provide the necessary structural support while having low enough stiffness to minimize the mass influence on panel velocity. The compliant elements act as decoupling mechanisms that allow the panel to achieve higher velocities without being dragged down by the actuator mass.
3Strength
If stiff material is used between actuator components and panel, then connection strength is improved, but the mass of the actuator has greater influence on panel movement
Solution Approach 1:
Flexible compliant elements (such as flexible membranes, thin flexible plates, or elastomeric mounts) are used to connect the actuator components to the panel. These flexible elements provide sufficient connection strength to hold the actuator assembly together while having low enough stiffness and mass to minimize their influence on panel movement. The flexibility of these elements allows them to deform with panel motion rather than restraining it, thereby maintaining high acoustic output.
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 enhances the panel's velocity and sound pressure level, particularly at high frequencies (5 kHz to 20 kHz), resulting in louder audio output compared to conventional actuator modules, with increased gain and resonance boosting the acoustic output.
Implementation Method 1
The actuator can be an electromagnetic actuator that includes one or more magnets and a voice coil positioned in the magnetic field of the one or more magnets. The one or more magnets can move relative to the voice coil to transfer a force to the panel of the panel audio loudspeaker.
Implementation Method 2
the spacer can be surrounded by a ring of compliant material that is positioned between the panel and certain components of the actuator module other than the coil. The compliant material can allow the certain components to couple weakly to the panel through the ring of compliant material.
Implementation Method 3
one or more springs connected to the frame and suspending the magnet assembly relative to the frame and intermediate layer
Data Source
AI summary
A panel audio loudspeaker includes an actuator module. The actuator module includes an intermediate layer. The intermediate layer has a voice coil connected to the intermediate layer at a first surface. The actuator module includes a magnet assembly including a plurality of magnets. At least one pair of magnets are separated by an air gap. The actuator module includes a frame connected to the intermediate layer at the first surface, one or more springs connected to the frame and suspending the magnet assembly relative to the frame so that the voice coil extends at least partially into the air gap, and a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface. A stiffness of the spacer at a region of connection to the intermediate layer is less than a stiffness of the intermediate layer at the connection portion.