Bosch Praesideo – Audio Expander

• Four audio inputs – two selectable mic/line and two line inputs
• Four line audio outputs
• Eight supervised control inputs and five control outputs
• Audio processing functions
• Redundant network connection

The audio expander inserts external audio into the system and extracts audio from the system. This unit has control inputs and outputs for external interfacing.
It can route its audio inputs permanently or conditionally to any of the zones or to other audio outputs. The routing conditions are configured using the configuration software. The audio output can be programmed to get its signal from any of the audio inputs. The equipment can be used freestanding (tabletop) or in a 19″ rack.

Functions
The audio expander has four transformer isolated analog audio inputs. Two of these are selectable between microphone and line. The other two inputs are fixed line inputs. The expander has four transformer isolated analog audio line outputs. It has
built-in digital audio processing capable of three parametric and two shelving equalizer sections for all audio in and outputs. They also have a selectable 20 kHz monitoring signal. The 2 x 16‑character display and the rotary control enable local status enquiries.
The display shows the VU-meter reading when audio monitoring mode is active. Audio can also be monitored by using a headphone. The eight control inputs are freely programmable for system actions, and priorities can be assigned to these
inputs. Each control input has the ability to monitor the attached line for open and short-circuits. Five control outputs are freely programmable for faults and
call-related actions. The audio expander supports redundant network
cabling. The network can be either single branch or redundant loop. The unit is powered from the network controller via the network cable. The expander is selfmonitoring and continuously reports its status to the network controller.

Controls and Indicators
• 2 x 16‑character LCD status display
• Rotary/push control for menu control and headphone volume

Interconnections
• Two system network connections
• Eight control inputs
• Two mic/line inputs
• Two line inputs
• Four line outputs
• Five control outputs
• Headphone output

Technical specifications
Electrical
Power consumption: 9 W (DC)
Performance
Frequency response: 20 Hz to 20 kHz (-3 dB)

Line inputs: 2 x
Connectors: 3-pin XLR and 2 cinch (for each line)
S/N: >87 dBA at maximum level
CMRR: >40 dB
Input range: +6 dBV to +18 dBV (XLR) -6 dBV to +6 dBV (cinch)

Mic / line inputs: 2 x
Connector: 3-pin XLR and 2 cinch (for each line)
Nominal Input Level: -57 dBV
S/N: >62 dBA with 25 dB headroom
CMRR: >55 dB at 100 Hz
Input Impedance: 1360 ohm
Phantom supply: 12 V ±1 V at 15 mA
Input range: -7 dB to 8 dB ref nominal input level

Line outputs: 4 x
Connectors: XLR and 2 cinch (for each line)
Output Impedance: <100 ohm
S/N: >89 dBA at maximum level
Crosstalk: <-85 dB
Signal range: -12 dBV to +18 dBV (XLR) -24 dBV to +6 dBV (cinch)
Distortion at 1 kHz: <0.05% Control inputs 8 x
Connectors: Removable screw terminals
Operation: Closing contact (with supervision)
Control outputs: 5 x
Connectors: Removable screw terminals