Acoustic Feedback - Bosch DCN Installation And User Instructions Manual

DCN Wireless | Installation and User Instructions | System Design and Planning
8.7

Acoustic feedback

Acoustic feedback ('howling') occurs when the sound of
the loudspeakers or headphones in the system is sent to
the system again by activated microphones.
table 8. 1 : Acoustic feedback
Source
The acoustic feedback is caused by
the loudspeakers of the contribution
devices.
The acoustic feedback is caused by
an external public address system
that is connected to the DCN
Wireless digital congress network.
The acoustic feedback is caused by
the headphones that are connected
to the contribution devices.
Bosch Security Systems | 2007-11 | 9922 141 70691 en
Quick solution
Decrease the volume level of the
system. For example, with the knob
on the front of the central control
unit (refer to section 10.6.3).
Decrease the volume level of the
public address system or the DCN
Wireless digital congress network.
Tell the chairmen and the delegates
to decrease the volume level of their
headphones with their contribution
devices.
Structural solution
Do as follows:
1 Install a feedback suppressor
between audio input 2 and audio
output 2 of the central control
unit.
2 Set the audio routing mode of
the system to Insertion (refer to
section 12.6).
Install a feedback suppressor
between audio output 1 and the
input of the external public address
system.
Install and configure the
headphones level reduction of the
contribution devices. (Refer to the
section about the contribution
devices.)
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