Question:
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What is the difference between a 3-pin XLR connector wired for balanced audio input / output and a 3-pin XLR connector wired to support a Clear-Com party-line system?
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I need to connect the party-line audio feed to an audio mixer input. Is this possible?
Answer:
The audio connections of both systems are different, the balanced audio feed is considered a 4-wire connection that doesn't use a Vdc component on any of the 3-pins of the XLR connector.
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A 3-pin XLR wired for Clear-Com intercom audio is considered an unbalanced 2-wire connection that uses a +30Vdc on one of the XLR pins to power various intercom stations, beltpacks and interfaces.
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The two disciplines are not compatible and in order to join them together an interface is required to bridge the unbalanced and balanced audio paths together.
Balanced 3-pin XLR audio pinouts (4-wire)
Clear-Com unbalanced intercom 3-pin XLR pinouts (2-wire)
Clear-Com manufacturers several different 2-wire to 4-wire interfaces for applications that require injecting intercom audio to a third party audio device such as a mixer, public address system and or a recording device.
Clear-Com interfaces:
EF-701M - Converts one channel of PL audio to balanced audio including direct connection to a Matrix frame or fiber optic devices
IF4W4 - Converts 4 channels of PL audio to balanced audio (for TV cameras, 2-way radios)
AC-701 - Converts one channel of PL audio to other 2-wire, 3-wire, 4-wire or telephone lines