Annular Ring Acoustic Transformer for Precise Sound Radiation Control
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Solution Overview
Problem
Existing audio speaker systems face challenges in tailoring the radiation angle of sound from a loudspeaker driver exit to achieve desired coverage, as prior techniques either widen or narrow the radiation pattern but not efficiently control the angle in-between, and fail to handle asymmetrical energy distribution effectively.
Innovation Solution
An acoustic transformer that transforms a planar or non-planar wave into a planar wave with uniform power distribution, using radial divisions that maintain equal path lengths and expansion rates for all acoustic paths, allowing for precise control of energy distribution and angle adjustment, including asymmetrical distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the driver exit pattern is narrower than desired coverage, then the horn walls cannot control the radiation pattern, but widening the pattern reduces directionality
Solution Approach 1:
The driver exit is divided into multiple segments (e.g., 4 quadrants) with independent acoustic paths. Each segment can be individually controlled to achieve desired radiation patterns. The segmentation allows precise control of energy distribution in different directions while maintaining overall pattern control.
Solution Approach 2:
The acoustic paths include variable impedance sections that can be dynamically adjusted to control the radiation pattern. By changing the impedance characteristics of different paths, the system can adapt the radiation angle and energy distribution to match desired coverage patterns.
2Shape
If rectangular slot transformation is used to control radiation angle, then directionality is improved, but asymmetrical energy distribution cannot be handled effectively
Solution Approach 1:
The invention explicitly incorporates asymmetrical acoustic path designs where different paths have different lengths, impedances, or cross-sectional areas. This allows independent control of energy distribution in different directions, enabling effective handling of asymmetrical radiation patterns while maintaining precise angle control.
Solution Approach 2:
Different segments of the driver exit are assigned different acoustic path characteristics tailored to specific directional requirements. Each local region can be optimized independently for its intended radiation direction, allowing precise control of both symmetrical and asymmetrical energy distribution.
3Shape
If horn length is increased to narrow coverage angle, then directionality is improved, but device length becomes impractically long
Solution Approach 1:
The invention uses cross-sectional segmentation and impedance variation in the transverse dimension to achieve angle control without increasing longitudinal length. By controlling acoustic impedance and energy distribution across multiple segments, the system narrows the radiation pattern in a compact configuration.
Solution Approach 2:
The acoustic impedance parameters of the segmented paths are specifically designed to control the radiation angle. By adjusting impedance ratios and path length differences, the system achieves narrow coverage angles through wave interference and energy distribution control rather than relying on long horn geometry.
4Shape
If vanes are added to spread acoustic energy, then radiation angle is widened, but device complexity increases
Solution Approach 1:
The segmented walls serving as path dividers also function as impedance control elements and energy distribution mechanisms. These structural elements perform multiple functions simultaneously: defining acoustic paths, controlling impedance, and distributing energy, thereby avoiding the need for separate vanes or additional complexity.
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
Enables precise control of sound radiation angles, accommodating a wide range of desired coverage patterns and energy distributions, improving the flexibility and effectiveness of sound wave propagation in audio speaker systems.
Implementation Method 1
an acoustic transformer that transforms a planar or non-planar wave into a planar wave with uniform power distribution
Data Source
Figure 1
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Figure 2b
AI summary
An acoustic transformer includes at least one outer boundary wall. A plurality of inner walls are disposed within the outer boundary wall. The outer boundary wall and the inner walls define an input opening divided by at least some of the inner walls into a plurality of input sections. A substantially annular output opening is divided by at least some of the inner walls into a plurality of circumferentially-spaced output sections. Each of the output sections has an inner circumferential side and an outer circumferential side. Each of a plurality of acoustic paths interconnects a respective one of the input sections with a respective one of the output sections. Each of the paths has a substantially equal path length and a substantially equal expansion rate.