Movable Acoustic Lens for Loudspeaker Directivity Control
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Solution Overview
Problem
Conventional loudspeaker assemblies lack the ability to control sound directivity effectively, especially in varying listening environments, and there is a need for a solution that can hide or protect speakers when not in use while maintaining high sound quality and minimizing distortions.
Innovation Solution
A loudspeaker assembly with a mechanically controlled acoustic lens featuring movable members that can alter directivity, combined with DSP-controlled filters and separate power amplifiers for each transducer unit, allowing precise control of sound distribution and reproduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional loudspeaker assembly is used, then the structure is simple and exposure protection is basic, but the ability to control sound directivity is insufficient and sound distribution cannot be adapted to varying listening environments
Solution Approach 1:
The acoustic lens incorporates movable members that can be dynamically repositioned to alter sound directivity. The lens structure transitions from a static configuration to a dynamic one where members can move between different positions to control sound distribution patterns, enabling adaptation to various listening environments while maintaining a relatively simple overall device architecture.
Solution Approach 2:
The acoustic lens is divided into multiple movable members that can be independently positioned. This segmentation allows each member to contribute to the overall sound directivity control, providing versatile sound distribution capabilities without requiring a completely complex device structure. The segmented approach enables precise control while keeping individual components manageable.
2Manufacturing precision
If DSP-controlled filters and separate power amplifiers are added for each transducer unit, then sound quality and directivity control are improved, but device complexity and manufacturing cost increase
Solution Approach 1:
Separate power amplifiers are assigned to each transducer unit (woofer, mid-range, tweeter) to provide optimized electrical characteristics for each frequency range. DSP-controlled filters are implemented specifically for each transducer to tailor the frequency response and directivity control to the specific requirements of each unit, thereby improving overall sound reproduction accuracy without uniformly increasing complexity across the entire system.
3Length of stationary object
If the acoustic lens is made shallow to minimize construction height, then the overall assembly height is reduced, but the ability to focus sound precisely in the vertical direction is limited
Solution Approach 1:
The acoustic lens maintains a shallow construction height while incorporating movable members that can dynamically adjust their positions to achieve precise sound focusing in the vertical direction. The dynamic repositioning capability compensates for the reduced physical depth, allowing the lens to focus sound accurately without increasing the overall construction height.
4Adaptability or versatility
If movable members are added to control horizontal plane directivity, then sound distribution control is enhanced, but the risk of interference and reflections from the movable surfaces increases
Solution Approach 1:
The movable members are designed with specific surface characteristics tailored to their function. The surfaces are configured to reflect sound in desired directions while minimizing unwanted reflections and interference. By optimizing the local surface properties of each movable member, the system achieves enhanced horizontal directivity control while mitigating the potential harmful effects of sound reflections from these surfaces.
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 provides versatile and precise control over sound directivity, minimizing distortions and reflections, and allows for the acoustic lens to be dynamically configured for optimal sound reproduction in any desired listening position, enhancing the overall audio experience.
Implementation Method 1
The movable members are reflecting the emitted sound and as such the shape of the movable members is important
Implementation Method 2
The particular advantages of redistributing the acoustic energy through an acoustic lens with a very well-defined distribution pattern are achieved with negligible distortion of the signal
Data Source
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AI summary
A loudspeaker assembly enabled with means to control the directivity of sound emitted from the loudspeaker and the use of such an assembly in audio rendering equipment. The inventive assembly includes an acoustic lens having movable mechanical means enabling controlled directivity of the sound emitted from the loudspeaker by moving one or more of the movable mechanical means from a first position to a second position.