Acoustic Waveguide Geometry for Directional Soundbar Playback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional acoustic waveguides for up-firing and side-firing transducers in playback devices, such as soundbars, face design challenges due to dimensions and shapes that complicate waveguide implementation, leading to insufficient directionality and horizontal leakage, which affects the psychoacoustic perception of sound localization.
Innovation Solution
The use of acoustic waveguides with specific sidewall geometries that accommodate the playback device's perimeter and provide a tall front portion to minimize horizontal leakage, while maintaining lateral dispersion for up-firing transducers and enhancing directionality for side-firing transducers, along with offset center tweeters to accommodate electronic components in a compact profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If conventional acoustic waveguides are used in playback devices with slim profiles, then the device can maintain a compact form factor, but the waveguide cannot provide sufficient directionality and suffers from horizontal leakage
Solution Approach 1:
The waveguide employs non-uniform sidewall heights around its perimeter, with the front portion being taller than the rear portion. This local variation in geometry creates different acoustic reflection characteristics at different locations, thereby improving directionality and reducing horizontal leakage while maintaining the overall compact profile of the playback device.
Solution Approach 2:
The waveguide is designed with asymmetric sidewall configurations where the front sidewall is taller than the rear sidewall. This asymmetric geometry breaks the symmetry of sound propagation, enhancing vertical directionality and minimizing horizontal sound leakage, which are critical for achieving immersive audio in compact devices.
2Reliability
If the waveguide front portion is made taller to reduce horizontal leakage, then directionality improves, but the device complexity increases
Solution Approach 1:
The waveguide is segmented into distinct portions with different sidewall heights - a front portion with greater height and a rear portion with lesser height. This segmentation allows each portion to serve its specific acoustic function while maintaining manufacturability through modular construction approaches.
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 enhances the directionality and performance of up-firing and side-firing transducers by reducing horizontal leakage and maintaining a wide soundstage, improving the psychoacoustic perception of sound localization, particularly in playback devices with slim profiles.
Implementation Method 1
an acoustic waveguide in fluid communication with the transducer, the waveguide comprising: a sidewall extending around an axis passing through the transducer, the sidewall having a height from the transducer that varies with an azimuthal angle about the axis
Implementation Method 2
an electroacoustic transducer; and an acoustic waveguide in fluid communication with the transducer
Data Source
AI summary
Acoustic waveguides can be used to improve audio performance of playback devices, such as a soundbar. Such a playback device can include an elongated body defining an outer perimeter with a forward surface, an upper surface, and a rounded edge between the forward surface and the upper surface. An up-firing transducer is configured to direct sound along an axis that has a vertical oblique angle with respect to a forward axis. A waveguide in fluid communication with the up-firing transducer includes a sidewall extending circumferentially around the transducer, the sidewall having a first end adjacent the up-firing transducer and a second end adjacent the outer perimeter, such that an opening defined by the sidewall has a larger area at the second end than at the first end. A rear portion of the sidewall is more steeply angled with respect to the axis than a forward portion of the sidewall.