Biamp AudiaEXPI/O-2 - Manual (Page 9)

9
APPLICATIONS
Courthouse with multiple courtrooms and hard-disk court recording
This application describes a major installation in four courtrooms, each with sound reinforcement of ten inputs. Each courtroom
includes an assisted listening system, as well as a centralized multi-track computer hard-disk court recording system and
localized sound reinforcement. This networked system uses four AudiaEXPO-4 Output Expander units and two AudiaFLEX
20x4 CM units with outputs feeding an MCA8050 Multi-Channel Amplifier. An example system diagram is shown on the
following page.
Each courtroom is shown as having ten microphones. Audia inputs accept microphone or line-level signals equally well, so
some inputs could instead be from sources such as playback of recorded evidence. Inputs from the four courtrooms are
connected to the two AudiaFLEX units, which are located in a local equipment closet. Each AudiaFLEX unit accommodates
inputs from two of the courtrooms and provides four system outputs. One unit provides the outputs necessary to feed a
hearing assistance system in each of the courtrooms. The other unit provides the outputs needed for sound reinforcement.
These outputs feed an MCA8050 Multi-Channel Amplifier.
The MCA8050 amplifier has eight channels that have been bridged in pairs, essentially creating four channels of 100 watts
each. With four TDT100 transformers installed internally, the MCA8050 is prepared to drive the 70-volt distributed speaker
system in each of the four courtrooms.
CobraNet and Ethernet from both AudiaFLEX units are tied together through separate Ethernet switches. This allows sharing
of digital audio signals (CobraNet) and control data (Ethernet) on their own networks. Also connected to, and functioning as
part of, the CobraNet network, are four AudiaEXPO-4 Output Expander units. These four AudiaEXPO-4 units are physically
located in a central computer/recording office. The maximum distance between any Audia unit and an Ethernet switch is 100
meters. Therefore, this system can span up to 300 meters between the equipment closet and the computer/recording office.
Additional Ethernet switches, or even fiber-optics, can further extend distances between units on the network.
Each AudiaEXPO-4 receives four channels of digital audio via CobraNet over a single CAT-5 cable. These four channels of
digital audio are then converted to analog audio and appear on four separate output connections. Each AudiaEXPO-4
provides the appropriate channels of audio for one of the four court recording systems. Mixing and processing of these signals
(to achieve proper microphone/track assignment and consistent recording levels) has been accomplished back at the
AudiaFLEX units.