Shure Conference Phone - Manual (Page 14)

English
5 AEC / Telco Audio Interface
This interface provides a dedicated termination to connect the discussion system directly to most external
telephone hybrids or videoconference codecs, enabling users of the system to communicate with remote
parties. When used in conjunction with a telephone hybrid, the Conference
ONE™ discussion system can
communicate with distant parties over standard telephone lines. When used in conjunction with a
videoconference codec, the Conference
ONE™ provides the audio portion of a videoconference. To avoid
returning echoes to the distant party, the device must provide effective acoustic echo control (AEC). The
Conference
ONE™ discussion system does not provide this echo control function.
5.1 Interface Levels
The interface provides professional balanced line level signals; a nominal
level of 0 or +4 dBu. Level Adjustment switches, set next to the terminal
blocks, allow for optimum level matching to a hybrid/codec that may require
higher or lower than nominal speech signal levels to properly operate. To
maintain the same input and output level the switches should be set to
the same position. If the hybrid/codec provides weaker than nominal
receive signal levels from the remote party (received speech in the
Conference
ONE™ loudspeakers is perceived to be lower in level than the
local speech), the switches can be set to the “-5 dB” positions to match the
lower than nominal Receive Input signal level. This will boost the received
speech heard from the loudspeakers and lower the level of transmitted
speech. The opposite effect results with the switches set to the “+5 dB”
positions. Note that these switches cannot be expected to compensate for
poor line conditions. For reliable teleconferencing, the external telephone
hybrid or videoconference codec needs to be capable of providing
consistent receive signal levels to the Conference
ONE™ over a range of
conditions.
5.2 Balanced / Unbalanced Connections
The 6-pin terminal block provides a balanced input and output audio connection to the system. If the
hybrid/codec uses unbalanced inputs and outputs, make connections to the Conference
ONE™ “+” terminals
and ground, leaving the “-” terminals open.
5.3 External Interface Device Settings
For information on the required settings of the external telephone hybrid or videoconference codec, refer to
its user guide.
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