Loudspeaker Diffuser Base Recessed Parts Front Room Effect
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing speakers with center caps and diaphragms experience front room effects, causing peaks or dips in sound pressure frequency characteristics due to interference between output sounds, which current diffusers fail to adequately suppress and adjust directivity characteristics.
Innovation Solution
A speaker design incorporating a diffuser base with recessed parts that separate the output sounds from the center cap and diaphragm, dispersing resonance frequencies and reducing interference, thereby enhancing directivity and suppressing front room effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a center cap with recessed part is used, then directivity adjustment is enabled, but front room effect causes peaks or dips in sound pressure frequency characteristics
Solution Approach 1:
The diffuser base is segmented into multiple recessed parts (first, second, and third recessed parts) at different positions and depths around the peripheral part. This segmentation creates multiple separate acoustic paths that disrupt the coherent interference pattern causing front room effect, while maintaining the directivity control function through the overall diffuser structure.
Solution Approach 2:
Different recessed parts are positioned at specific locations (front, rear, and side positions) with varying depths relative to the diaphragm front surface. This local variation in recessed part geometry creates position-dependent acoustic characteristics that suppress front room effect in specific frequency ranges while preserving directivity control in other ranges.
2Adaptability or versatility
If a diffuser is added to adjust directivity, then directivity characteristics can be controlled, but front room effect suppression is insufficient
Solution Approach 1:
The diffuser incorporates multiple recessed parts distributed around the peripheral part of the center cap, creating segmented acoustic paths. This segmentation disrupts the coherent sound waves that cause front room effect while maintaining the diffuser's ability to control directivity through its overall geometry and position.
Solution Approach 2:
The recessed parts act as intermediary structures between the sound source (center cap and diaphragm) and the surrounding environment. These recessed parts modify the acoustic field by creating localized volume changes and sound path variations, thereby suppressing front room effect without interfering with the diffuser's primary directivity control function.
3Reliability
If recessed parts are added to suppress front room effect, then sound pressure frequency characteristics improve, but device complexity increases
Solution Approach 1:
The recessed parts are integrated into the diffuser base structure as a unified component rather than separate attachments. The first, second, and third recessed parts are formed as part of the same molded structure, combining the diffuser's directivity control function with the front room effect suppression function in a single integrated part.
Solution Approach 2:
The diffuser base serves multiple functions simultaneously: it controls directivity characteristics through its overall geometry and position, suppresses front room effect through the recessed parts, and maintains structural integrity as a single component. This multi-functionality reduces the need for additional separate components.
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 diffuser base with recessed parts improves sound pressure and directivity characteristics, particularly in high-frequency ranges, by minimizing interference and expanding the sound field, allowing for clearer and more balanced sound reproduction.
Implementation Method 1
an output sound from the center cap interferes with an output sound from the diaphragm in a space positioned closely in front of the recessed part, so that a peak or dip may be generated in a specific frequency
Implementation Method 2
a peak or dip may be generated in a specific frequency to disturb its sound pressure frequency characteristics
Implementation Method 3
a technique of arranging a diffuser for adjusting the directivity of output sound in front of the center cap
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A speaker (51) includes a vibrating body (67) having an annular valley portion (Qa) recessed rearward and a diffuser (9) having an annular or arcuate base part (9b), which is positioned so that an end (9c) of the base part (9b) on the side of the vibrating body (67) is opposed to the valley portion (Qa). The base part (9b) is provided, at the end (9c) on the side of the vibrating body (67), with one or more recessed parts (E) from which distance to the vibrating body (67) is larger than a distance of the other portion of the end to the vibrating body (67).