Loudspeaker Vibrator Placement for Casing Vibration Control
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Solution Overview
Problem
Conventional loudspeakers experience unwanted vibrational forces that cause casing rattling or buzzing due to passive radiators, necessitating costly vibration dampening and isolation measures.
Innovation Solution
A loudspeaker design featuring a housing with a driver module and a vibrator module, where pairs of first and second vibrators are strategically positioned on opposite sides of the housing to generate balanced vibrational forces, eliminating torque and vibration issues by ensuring symmetry and balanced oscillation with the driver cone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a passive radiator is used to increase sound-pressure-level, then the lower-frequency sound output is improved, but unwanted vibrational forces cause the casing to rattle or buzz
Solution Approach 1:
The patent uses asymmetric placement of passive radiators relative to the driver cone, positioned at specific angles and distances to create destructive interference of vibrational forces while maintaining constructive interference for sound waves. This asymmetric configuration cancels out the harmful vibrational forces that cause casing rattling and buzzing.
2Object-generated harmful factors
If vibration dampening and isolation means are added to reduce casing vibration, then the harmful vibrations are reduced, but the device complexity and cost increase
Solution Approach 1:
The patent converts the harmful vibrational forces generated by passive radiators into a beneficial cancellation effect by strategically positioning additional passive radiators to create opposing vibrational forces. Instead of using dampening materials to suppress vibrations, the system uses the vibrations themselves to cancel each other out, eliminating the need for complex vibration isolation structures.
3Stability of the object's composition
If two passive radiators are placed on opposite sides of the speaker cone, then the torques are balanced out, but the vibrational forces themselves are not balanced and still cause rattling
Solution Approach 1:
The patent extends the asymmetric positioning principle to multiple passive radiators arranged in a specific three-dimensional configuration around the driver cone. This asymmetric arrangement ensures that both the torques and the linear vibrational forces are balanced through precise geometric relationships, rather than simple opposite-side placement.
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 balanced vibrational forces prevent the loudspeaker casing from vibrating, reducing the need for complex and costly vibration dampening and isolation means, thereby minimizing rattling and buzzing.
Implementation Method 1
the sound waves generated/emitted from the passive radiator and the speaker cone add together to create an increase in sound-pressure-level
Implementation Method 2
the passive radiator also generates unwanted vibrational forces in different directions that cause the casing to rattle or buzz
Implementation Method 3
The vibrational forces generated by the passive radiators are equal in magnitude and direction, and respectively act on the opposite sides of the speaker cone. As such, the torques exerted by the vibrational forces with respect to a center of the speaker cone are balanced out
Data Source
AI summary
A loudspeaker includes a housing, a driver module and a vibrator module. The housing has a first wall section, and a second wall section that is spaced apart from the first wall section in a first direction. The driver module is mounted to the housing and includes at least one driver cone. The vibrator module includes a pair of first vibrators that are disposed on the first wall section and that are respectively located at two opposite sides of the driver module in a second direction perpendicular to the first direction and a pair of second vibrators that are disposed on the second wall section and that are respectively located at two opposite sides of the driver module in the second direction.