Acoustic Device Flexible Partition Bass Response
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Solution Overview
Problem
Traditional acoustic systems, especially miniature ones, face challenges in reproducing bass effectively due to volume limitations, and existing solutions like sound absorption materials and passive radiators either damage the loudspeaker or only enhance sensitivity near a specific frequency, failing to improve sensitivity across all low frequency bands.
Innovation Solution
An acoustic device with a sound generating unit and a divided closed cavity system, where a flexible partition adjusts the volume of the first closed cavity, and the second closed cavity encloses sound waves generated during deformation, reducing resonance frequency and enhancing low-frequency sensitivity by isolating anti-phase sound waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If sound absorption materials are added to the box to increase volume and reduce resonance frequency, then low frequency resonance frequency is reduced, but the sealing package requirement increases and risk of damaging loudspeaker unit increases
Solution Approach 1:
The patent uses a flexible membrane instead of rigid sound absorption materials. The membrane can be flexibly deformed by sound pressure changes to adjust cavity volume, eliminating the need for complex sealing packages while avoiding damage to the loudspeaker unit.
Solution Approach 2:
The patent transforms the static cavity volume into a dynamic one by introducing a flexible membrane that can be flexibly deformed according to sound pressure changes, allowing real-time adjustment of cavity volume to reduce resonance frequency without adding complex sealing structures.
2Manufacturing precision
If a passive radiator is provided to enhance sensitivity near resonance frequency point, then local sensitivity near fp is enhanced, but sound waves counteract in frequency band below fp reducing overall sensitivity
Solution Approach 1:
The patent divides the closed cavity into two separate cavities: a first closed cavity adjacent to the vibration diaphragm for sound generation, and a second closed cavity for enclosing counteracting sound waves. This segmentation prevents the counteraction effect while maintaining the benefits of each cavity.
Solution Approach 2:
The patent extracts the counteracting sound waves generated by the flexible membrane's deformation into a separate second closed cavity, isolating them from the main sound field. This removes the harmful counteraction effect while preserving the volume adjustment benefit for resonance frequency reduction.
3Manufacturing precision
If cavity volume is increased to improve bass reproduction, then low frequency sensitivity is improved, but device size increases
Solution Approach 1:
The patent uses a flexible membrane that can be flexibly deformed to dynamically adjust the cavity volume. This allows the cavity to effectively increase in volume for bass reproduction while maintaining a compact physical device size, as the volume expansion is achieved through membrane deformation rather than physical expansion.
Solution Approach 2:
The patent changes the physical state of the cavity boundary from rigid to flexible, allowing the cavity volume parameter to change dynamically in response to sound pressure. This enables effective volume increase for low frequency sensitivity without permanently increasing the device's external dimensions.
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 effectively reduces resonance frequency and improves low-frequency sensitivity across the board, avoiding counteractive sound waves and maximizing the use of internal space for a thinner, more efficient acoustic design.
Implementation Method 1
When the vibration diaphragm vibrates, the internal sound pressure of the first closed cavity is changed, and a flexible deformation part of the partition part deforms with the change of the sound pressure in the first closed cavity
Implementation Method 2
at least a portion of the partition part may be flexibly deformed
Implementation Method 3
the second closed cavity encloses the sound waves generated by the flexible deformation part during deformation into the second closed cavity
Implementation Method 4
the sound waves at a front side of the vibration diaphragm is radiated to the outside through the sound outlet
Data Source
AI summary
An acoustic device comprises a sound generating unit having a vibration diaphragm, the acoustic device is provided with a sound outlet, the sound waves at a front side of the vibration diaphragm radiates to the outside through the sound outlet; and an enclosed closed cavity formed at a rear side of the vibration diaphragm, the closed cavity is divided into first and second closed cavities by a partition part, and at least a portion of the partition part flexibly deforms, the first closed cavity is adjacent to the vibration diaphragm, the second closed cavity is far away from the vibration diaphragm, the volume of the second closed cavity is larger than that of the first closed cavity; the second closed cavity encloses the sound waves into the second closed cavity; at least a part of an electronic apparatus housing is used for forming the first and/or the second closed cavity.