Compact Horn Speaker with Folded Ring Resonator
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Solution Overview
Problem
Existing sound reproduction systems fall short in achieving wide bandwidth, high fidelity, and compact size, often resulting in limited frequency range, high harmonic distortion, and large size due to the physical constraints of bass horns and other speaker topologies.
Innovation Solution
A compact horn-type loudspeaker design featuring a front-loaded horn with a ring resonator and feedback duct, which extends the bass frequency range to 20 Hz to 1.5 kHz with low harmonic distortion and high efficiency, using a folded ring resonator and feedback duct configuration to control energy transfer and phase alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If bass horns are made physically large to achieve extended bass frequency range, then low frequency reach is improved, but device size becomes excessively large
Solution Approach 1:
The patent implements a folded horn design where the acoustic path is nested within a compact enclosure. The horn folds back on itself multiple times, allowing a long acoustic path (4.2+ meters for 20 Hz) to be contained within a much smaller physical footprint, resolving the contradiction between extended bass range and compact size
Solution Approach 2:
The patent transitions from a linear horn configuration to a three-dimensional folded structure. By utilizing vertical and lateral dimensions through folding passages, the design achieves the required acoustic length without proportionally increasing the enclosure volume, enabling deep bass in a compact form factor
2Power
If cone motion is increased to achieve higher sound pressure level, then SPL is improved, but harmonic distortion increases
Solution Approach 1:
The patent employs a feedback duct that connects the rear chamber to the front horn, creating an acoustic feedback loop. This feedback mechanism controls cone motion by providing acoustic resistance, allowing the system to achieve high SPL (98 dB at 1 meter) while maintaining low total harmonic distortion (0.03% at 50 Hz) through controlled damping of excessive cone excursions
3Volume of stationary object
If horn size is reduced to achieve compact design, then device size is improved, but bandwidth is limited
Solution Approach 1:
The patent segments the acoustic system into distinct functional zones: front compression chamber, rear chamber, ring resonator, and feedback duct. Each segment is optimized for specific frequency ranges, with the ring resonator handling lower frequencies and the front horn handling midrange, achieving a bandwidth of 7+ octaves (20 Hz to 1.5 kHz) in a compact enclosure
Solution Approach 2:
The patent makes the front horn serve multiple functions: it acts as both the primary radiating horn for midrange frequencies and as part of the feedback path for controlling bass frequencies. This multi-functionality allows a single compact structure to handle a wide frequency range without requiring separate large components for each frequency band
4Power
If sealed back cavity is used to control cone motion, then SPL is improved, but bandwidth is restricted
Solution Approach 1:
The patent introduces a feedback duct as an intermediary element that connects the sealed back cavity to the front horn. This feedback duct provides a controlled acoustic pathway that allows the sealed cavity to maintain its SPL benefits while the feedback mechanism extends the bandwidth by enabling lower frequency resonance and improving overall system responsiveness across a 7+ octave range
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 achieves a flat frequency response, low harmonic distortion, and reduced size, enabling efficient sound reproduction across a wide range while minimizing audio power requirements and cone motion, suitable for various applications from home theaters to public venues.
Implementation Method 1
A compact horn-type loudspeaker design featuring a front-loaded horn with a ring resonator and feedback duct, which extends the bass frequency range to 20 Hz to 1.5 kHz
Implementation Method 2
a folded ring resonator and feedback duct configuration to control energy transfer and phase alignment
Implementation Method 3
A compact horn-type loudspeaker design featuring a front-loaded horn with a ring resonator and feedback duct
Implementation Method 4
a folded ring resonator and feedback duct configuration to control energy transfer and phase alignment
Data Source
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AI summary
The invention is a compact high fidelity sound reproduction system achieving high efficiency, low distortion, wide bandwidth, and extended low frequency reach and which can be used as a sub-bass woofer, bass woofer, mid-bass woofer, and mid-range speaker for residential or commercial large venue applications. The system includes a dynamic driver driven bass horn, a looped resonator duct (ring geometry), which can be folded, and an adjustable feedback duct allowing sound characteristics to be tailored.