Hollow Guitar Body Free Edge Reduces Low Frequency Coupling
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Solution Overview
Problem
Hollow-bodied stringed instruments suffer from bass-heavy tone and feedback due to low frequency resonance, which existing designs amplify, while high frequency resonance is desirable for tone quality.
Innovation Solution
A hollow-bodied stringed instrument body with at least one plate featuring a substantially free edge to attenuate low frequency resonance, maintaining high frequency resonance for tone quality, by altering the physical characteristics of the plates and enclosed volume to reduce coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the lower bout of each plate is left intact to maximize resonance and loudness, then the characteristic sound of hollow-bodied stringed instruments is enhanced, but bass-heavy tone and feedback occur due to low frequency resonance coupling
Solution Approach 1:
The lower bout of each plate is divided into two parts: a fixed portion that remains attached to maintain high frequency resonance and structural integrity, and a free portion that is released to attenuate low frequency coupling. This segmentation allows different parts of the same component to serve different functions - the fixed portion preserves desirable resonance characteristics while the free portion eliminates harmful bass-heavy tone and feedback.
2Productivity
If resonance is maximized to provide characteristic sound and loudness, then tone quality is improved, but low frequency coupling causes bass-heavy tone
Solution Approach 1:
Different regions of the plate are given different mechanical properties: the upper bout and bridge area maintain full attachment to preserve high frequency resonance and loudness, while the lower bout is partially released to create a free edge that specifically targets low frequency coupling. This local differentiation of mechanical properties allows selective attenuation of harmful low frequency resonance while preserving desirable high frequency characteristics.
3Object-generated harmful factors
If the body structure is modified to reduce low frequency coupling, then bass-heavy tone is reduced, but the characteristic sound of hollow-bodied instruments may be compromised
Solution Approach 1:
The plate attachment is segmented rather than completely removed - only the lower bout is released while the upper bout and bridge area remain firmly attached. This partial segmentation maintains the structural integrity and high frequency resonance characteristics essential to hollow-bodied instrument sound, while selectively eliminating low frequency coupling that causes bass-heavy tone.
Solution Approach 2:
The modification applies local quality changes only where needed - the lower bout edge is released to attenuate low frequency coupling, while the rest of the plate maintains its traditional attached structure to preserve high frequency resonance and characteristic sound. This localized approach ensures the characteristic sound is not compromised.
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
This design effectively reduces bass-heavy tone and feedback, allowing for balanced tone control and reduced pickup motion, eliminating the need for electronic adjustments and minimizing feedback when used with pickups.
Implementation Method 1
low frequency resonance that is most responsible for bass-heavy tone and feedback in hollow-bodied guitars
Implementation Method 2
The free edge attenuates low frequency coupling of the plate with the opposing plate and the enclosed volume of air
Data Source
AI summary
An improved hollow-bodied stringed instrument body having a substantially free edge in the lower bout which reduces the coupling of the resonances of the front plate, back plate, and enclosed volume of air. A selected number of holes of a selected shape create a substantially free edge in the lower bout of the front plate. This substantially free edge reduces the large-amplitude displacement of these plates that occurs due to low frequency resonance coupling. Placement of the free edge allows high frequency resonance of the front plate, which is not due to coupling, to contribute to the tone of the instrument. Reducing the large-amplitude displacement of the plates reduces bass-heavy tone and feedback.