Coaxial Loudspeaker Waveguide Apertures for Consistent Summation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional coaxial loudspeaker designs face issues with inconsistent frequency response and intermodulation distortion due to asymmetry and waveguide configurations that compromise high-frequency performance or block low-frequency energy, leading to inefficient use of acoustic volume and limited bandwidth.
Innovation Solution
A loudspeaker design featuring a coaxial transducer assembly with a waveguide that includes apertures to control radiation patterns and seal internal volume, allowing for optimized high-frequency distribution and extended low-frequency extension by venting energy through the waveguide, while maintaining acoustic impedance match and providing flexible beamwidth control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a large waveguide is used in a coaxial design, then high frequency performance consistency is improved, but low frequency energy is blocked causing lobing and inconsistent summation
Solution Approach 1:
The waveguide is segmented with multiple apertures distributed across its surface, allowing different frequency ranges to pass through different paths. Low frequency energy passes through the apertures while high frequency energy is directed through the main waveguide path, resolving the blocking issue.
Solution Approach 2:
Different regions of the waveguide are given different functions: the main waveguide body optimizes for high frequency distribution while the aperture regions are optimized for low frequency passage, allowing each region to perform its specialized function without interfering with the other.
2Reliability
If a small waveguide is used in a coaxial design, then low frequency energy can pass around the waveguide, but high frequency performance consistency is compromised
Solution Approach 1:
The waveguide expands from a simple linear structure to a three-dimensional form with apertures distributed across its surface area. This dimensional expansion allows the waveguide to simultaneously handle both low frequency energy (passing through apertures) and high frequency energy (through the main path) without compromise.
3Manufacturing precision
If a large waveguide is used, then coverage control extends to lower frequencies, but internal acoustic volume is reduced resulting in less bandwidth
Solution Approach 1:
The waveguide incorporates a porous aperture structure that allows acoustic energy to pass through the waveguide body itself. This porous approach maintains the external dimensions needed for coverage control while preserving internal acoustic volume through the aperture paths.
4Manufacturing precision
If the waveguide blocks the cone area, then high frequency distribution is optimized, but low frequency lobing occurs causing inconsistent summation
Solution Approach 1:
The apertures act as intermediary passages that allow low frequency energy to bypass the waveguide structure that optimizes high frequency distribution. This intermediary path prevents the blocking effect from causing lobing while maintaining the benefits of the optimized waveguide for high frequencies.
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 achieves consistent frequency response across multiple passbands by optimizing waveguide geometry and aperture placement, enhancing beamwidth control, and efficiently utilizing cabinet volume for improved sound quality and extended frequency range.
Implementation Method 1
The waveguide is coupled to the first transducer and configured to provide an acoustic impedance match between the first transducer and free air
Implementation Method 2
The waveguide includes a first plurality of apertures that enables acoustic energy radiated from a first radiating surface of the second transducer to pass through the waveguide and merge with acoustic energy radiated by the first transducer
Implementation Method 3
The first plurality of apertures extends through an expansion region of the waveguide. The shape of the waveguide controls a radiation pattern of acoustic energy radiated through the waveguide from the first transducer
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A loudspeaker includes a cabinet, a coaxial transducer assembly, and a waveguide. The coaxial transducer assembly includes a first transducer and a second transducer that is coupled to the first transducer and arranged such that respective motion axes of the transducers are coaxial. The waveguide is coupled to the first transducer and configured to provide an acoustic impedance match between the first transducer and free air. The waveguide includes a first plurality of apertures that enables acoustic energy radiated from a first radiating surface of the second transducer to pass through the waveguide and merge with acoustic energy radiated by the first transducer. The first plurality of apertures extends through an expansion region of the waveguide.