Dual Transducer Mobile Audio System for Compact Stereo
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Solution Overview
Problem
Existing mobile devices struggle to achieve a good stereophonic effect while maintaining a small size, as they typically use a single transducer for both voice and music, which compromises on frequency range and bulkiness.
Innovation Solution
A mobile terminal is equipped with at least two transducers, where one is a main transducer covering the standard phone frequency band and another secondary transducer with a higher frequency range extending beyond the main band's low frequencies, allowing for a stereophonic effect without increasing the device's size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a single transducer is used for both voice and music, then the device size is kept small, but the frequency range and sound quality are compromised
Solution Approach 1:
The audio output function is segmented into two separate transducers: a main transducer for voice communication (300-3400 Hz) and a secondary transducer for music playback (extending to 20 kHz). This segmentation allows each transducer to be optimized for its specific frequency range, achieving good sound quality for both voice and music while keeping the overall device size compact.
2Adaptability or versatility
If two identical transducers are used for stereophonic effect, then the stereo effect is achieved, but the device size increases
Solution Approach 1:
The two transducers are designed with different local qualities - the main transducer is optimized for voice frequency response while the secondary transducer is optimized for extended high-frequency music playback. This differentiation in local quality allows the system to achieve stereophonic effect for music without requiring two identical large transducers, thus maintaining a compact device size.
3Adaptability or versatility
If a specific transducer is designed for good music sound, then the frequency range is improved, but the transducer size becomes large
Solution Approach 1:
The music playback function is segmented from voice communication and assigned to a dedicated secondary transducer. This transducer is specifically designed with extended frequency response capabilities for music (up to 20 kHz) while maintaining a compact size. The segmentation allows the secondary transducer to be smaller than a full-range transducer would be, as it only needs to handle the high-frequency music range.
Solution Approach 2:
The secondary transducer, while optimized for music, can also serve dual purposes by contributing to the overall stereo effect and providing additional audio output capability. This multi-functionality justifies its inclusion without significantly increasing device size, as it serves both music playback and enhanced audio output functions.
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 provides a robust stereophonic effect for both voice and music signals without enlarging the device, as the secondary transducer's high-frequency range contributes to the sound without needing larger dimensions.
Implementation Method 1
a mobile terminal provided with several (at least two) transducers used as loudspeakers for stereophonic effect
Data Source
AI summary
The invention concerns a mobile terminal with at least two transducers (LSm, LSs1, LSS2) used simultaneously as loudspeakers for stereophonic effect. According to the invention, one of said transducers is a main transducer (LSm) with a main working frequency band (Bm) corresponding to at least the phone frequency band, while the other transducer is a secondary transducer (LSs1; LSs2) with a secondary working frequency band (Bs1; Bs2) band different from said main frequency band, the lowest frequencies of said secondary working frequency band (Bs1; Bs2) being greater than the lowest frequencies of said main working frequency band.