Bosch PRAESENSA PRA-SCL Configuration Manual page 98

98 en | Configure the system
Item
Low‑pass
filter
Set a filter and output
Proceeds as follows to set the filters of each output separately.
1.
2.
3.
4.
5.
6.
7.
Spare amplifier output channel
The integrated spare amplifier audio output channel automatically replaces a failing audio
output channel, with due regard of the actual sound processing settings. Meaning that the
spare amplifier audio output channel does not provide volume and equalizer settings for the
audio output channel. These settings are automatically set to the same position as the failing
audio output channel that is replaced by the spare audio output channel. No separate audio
options settings for the spare amplifier output channel are required. Refer to the PRAESENSA
installation manual (amplifier chapters) for a detailed description of the spare amplifier output
channel function.
Lifeline audio input
Each amplifier incorporate a (backup) analog lifeline audio input driving the spare amplifier
audio output channel to serve all connected loudspeaker zones in case the network
connections, or the amplifier network interface, would fail. The lifeline is automatically added
as a zone when adding a multifunction power supply (mps) in System composition, page 40
2020-09 | V1.20 | PRAESENSA 1.20
Filter
Make sure that all loudspeakers are connected to each amplifier output, set at the
correct power level, are aimed (if necessary) and are working.
The frequencies, gain and quality factors of each output are already set to the default
values as indicated in the previous table:
– IMPORTANT: The correct output setting depends on the environment to where the
audio output signal is routed to, and possible needs to be adjusted in the zone(s)
locally.
Enable (checkmark) the Active box of each filter for each output to enable it and to make
it active in the system.
Select the output volume level from the Volume dropdown list (default 0 dB):
– Adjust the nominal output level of the audio output in the zone to the level required
to have the correct speech intelligibility at maximum ambient noise level. It ranges
from 0 dB to -60 dB in steps of 1 dB and Mute.
If required, Enter the delay time in ms in the Delay text box (default 0 ms):
– Make sure that the audio delay setting of each applicable amplifier output is set to a
correct value. Very long delay settings (> 2 seconds), e.g. for tunnel applications,
may cause wrong calibration results.
– By entering the delay time the distance in meter/feet will be calculated and
displayed.
Click the Apply button:
– Be aware that the changes are immediately applied to the audio output and could
cause unexpected high‑level audio output in the loudspeaker zone(s).
Click the Submit button to submit the changes.
– Notice that audio processing parameters are changed immediately when also the
Submit button is clicked. Although the changes are audible, it is important to realize
that they are not automatically saved. If the changes are not saved they will be lost
when the system controller resets. See Save configuration, page 102 .
Value Description
Enter F Default: Frequency 10000 Hz, Quality factor 0.7
Select Q (selectable 0.2 ‑ 2.0).
Fixed: Gain -12 dB/oct.
Configuration manual
PRAESENSA
Bosch Security Systems B.V.