Hermetically Sealed Loudspeaker Driver Synchronization
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Solution Overview
Problem
Conventional loudspeakers face challenges in eliminating back pressure due to the asynchronous movement of drivers, leading to incomplete energy conversion and reduced sound accuracy.
Innovation Solution
A hermetically-sealed loudspeaker design featuring a first driver outside the enclosure and a second driver inside, connected by a pipe to form a sealed space, with the second driver producing a signal of opposite phase to cancel back pressure and enhance synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a tandem drive system with two drivers is used to cancel back pressure, then the back pressure problem is partially addressed, but the drivers do not operate in exact synchronization due to air movement delay
Solution Approach 1:
The second driver is nested inside the enclosure formed by the first driver's frame, with both drivers sharing a common hermetically-sealed internal space. This nesting arrangement allows the pipe to connect the drivers through the shortest possible path while maintaining exact synchronization of their operation.
Solution Approach 2:
The invention transitions from a sequential air-based pressure equalization system to a direct mechanical coupling system by placing both drivers in the same hermetically-sealed space and connecting them via a pipe, enabling synchronous operation in a three-dimensional configuration.
2Object-generated harmful factors
If a flat baffle plate is used to avoid back pressure, then back pressure is eliminated, but an enormous flat baffle plate is required which is not practical
Solution Approach 1:
The invention divides the driver system into two separate drivers (first and second drivers) positioned at different locations, each contributing to back pressure cancellation through their coordinated operation, thereby eliminating the need for a large flat baffle plate.
Solution Approach 2:
Instead of using a large two-dimensional flat baffle plate, the invention uses a three-dimensional configuration with two drivers positioned at different depths relative to the enclosure, achieving back pressure cancellation through spatial distribution rather than surface area.
3Volume of stationary object
If the pipe connects the two drivers in the shortest distance, then the space connecting the drivers is minimized, but the manufacturing precision required increases
Solution Approach 1:
The second driver is nested within the enclosure formed by the first driver's frame, allowing the pipe to connect them through the shortest possible distance while maintaining a hermetically-sealed environment. This nesting reduces the connecting space volume to the minimum required.
Solution Approach 2:
Instead of connecting drivers through a large external enclosure, the invention inverts the approach by placing one driver inside the enclosure formed by the other driver's frame, minimizing the connecting space and reducing manufacturing complexity.
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 configuration ensures exact synchronization of drivers, improving resonant frequency and achieving clear, accurate sound reproduction by canceling back pressure and reaction, allowing for faithful sound reproduction without distortion.
Implementation Method 1
The second driver is configured to output a signal of opposite phase to that of the first driver
Implementation Method 2
forming one hermetically-sealed space enclosed with the diaphragms and the frames of the two drivers
Data Source
Figure 1~2
AI summary
A loudspeaker 1 according to the present invention comprises a hermetically-sealed enclosure 3, a first driver 2a arranged at outside of the enclosure 3 and along a wall of the enclosure 3, a second driver 2b arranged at inside of the enclosure 3 and parallel to the first driver 2a across the wall of the enclosure 3 from the first driver 2a, and a pipe 7 communicating the first driver and the second driver. Each of the drivers 2a and 2b has a diaphragm 4, and a frame 5 surrounding the diaphragm 4. The frame 5 has an opening 5a. The pipe 7 is connected to the opening 5a of the frame 4 of the first driver 2a, penetrates through the wall of the enclosure 3, and is connected to the opening 5a of the frame 4 of the second driver 2b, and thereby forming one hermetically-sealed space enclosed with the diaphragms 4 and the frames 5 of the two drivers 2a and 2b. The second driver 2b is configured to output a signal of opposite phase to that of the first driver 2a. Thus, reaction of the diaphragm 4 can be canceled, and a problem of back pressure of the loudspeaker 1 can be removed.