Infinite-Baffle Loudspeaker Assembly With High-Tuned Helmholtz Resonator
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Solution Overview
Problem
Infinite baffle topology loudspeaker systems in vehicles face structural weakening due to large holes required for sound projection, and prior art solutions using Helmholtz resonators are inherently large, limiting low frequency extension and requiring larger speaker sizes.
Innovation Solution
A loudspeaker assembly with a compact Helmholtz resonator system, where the resonator chamber is dimensioned to provide a tuned frequency well above the operating band, allowing for smaller speaker sizes and enhanced low frequency extension by interacting with the driver's parallel resonant circuit components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional Helmholtz resonators are used to extend low frequency response, then low frequency extension is improved, but the system size increases and becomes inherently large
Solution Approach 1:
The patent applies parameter changes by tuning the Helmholtz resonator to a frequency well above the operating band rather than at or near the bottom end. This unconventional parameter adjustment allows the resonator to provide low frequency extension through interaction with the driver's parallel resonant circuit, enabling compact system size while achieving extended low frequency response below 300 Hz
Solution Approach 2:
The patent inverts the traditional approach by tuning the Helmholtz resonator higher rather than lower. Instead of tuning at or near the bottom end of the operating band to extend low frequency, the resonator is tuned well above the operating band, creating a counter-intuitive solution that achieves low frequency extension through resonant interaction while maintaining compact dimensions
2Ease of operation
If large holes are cut in vehicle structures for infinite baffle topology, then sound projection is improved, but structural integrity deteriorates
Solution Approach 1:
The patent extracts the sound projection function from the baffle structure by using a Helmholtz resonator with a vent duct that channels sound through a much smaller opening. This allows the infinite baffle topology to maintain structural integrity while still achieving effective sound projection to the listening environment through the resonator's tuned acoustic pathway
3Reliability
If Helmholtz resonators are tuned traditionally to extend low frequency, then low frequency response is improved, but the system becomes inherently large and complex
Solution Approach 1:
The patent changes the tuning parameter of the Helmholtz resonator from traditional low-frequency tuning to high-frequency tuning well above the operating band. This parameter change simplifies the system design by allowing the use of smaller resonator chambers while achieving low frequency extension through resonant interaction with the driver, reducing both physical size and design 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
The solution enables a smaller, high-sensitivity loudspeaker assembly with extended low frequency response, suitable for various applications, including vehicles, without compromising structural integrity or increasing size, while minimizing air noise and environmental exposure.
Implementation Method 1
at least one Helmholtz resonator including a chamber and a vent duct communicating with said chamber and adapted to pass through said infinite baffle, wherein said chamber is dimensioned to provide a tuned frequency well above an operating band associated with said driver
Implementation Method 2
the components of the series resonant circuit interact with the components of the parallel resonant circuit to produce: a lower tuned frequency which determines a low frequency roll off commonly called the 'low cut off frequency'
Data Source
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AI summary
A loudspeaker assembly is disclosed for use in a loudspeaker system having infinite baffle topology. The assembly comprises a driver including a cone and a basket and at least one Helmholtz resonator including a chamber and a vent duct communicating with the chamber and adapted to pass through the infinite baffle. The chamber is dimensioned to provide a tuned frequency well above an operating band associated with the driver. The cross sectional area and length of the vent duct may be set to provide control over duct air noise and low frequency extension. A method of tuning a loudspeaker assembly for use in a loudspeaker system having infinite baffle topology is also disclosed.