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US1881583A
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Phonograph
|
|
US1781376A
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Electrodynamic sound recorder and reproducer
|
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US1819210A
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|
Loud speaker
|
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Electrical adapter device
|
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Electrical vibrating motor
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Art of assembling loud-speakers
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Cabinet
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Loud-speaker driving motor
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Loud speaker
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Sound-regenerating device
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Sound reproducer
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Sound-producing device
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Sound-reproducing device
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Metal-coated diaphragm
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Amplifier horn
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Sound amplifier
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Sound amplifier
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Method of producing sound-amplifying horns
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CA310909A
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Telephone instrument
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CA301274A
|
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Balanced armature sound reproducer
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