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NEXUS for the Public Address System in the Bundestag

Joint project of Siemens and STAGETEC


Berlin, September 2018: The German Bundestag is currently larger than ever before in its history. It is not easy for members of parliament to keep track of who is speaking during plenary sessions. The NEXUS audio network from STAGETEC, the Berlin-based manufacturer of professional audio technology, and the Siemens S7 control system help with orientation as to which corner of the plenary hall is currently giving the floor.


A NEXUS audio network with five Base Devices is installed in the plenary hall. Directional sound reinforcement via the level-delay matrix in the NEXUS network ensures that the microphones of the delegates are located where they are positioned. For this purpose, STAGETEC developed the S7 interface, which establishes a connection between the NEXUS protocol and the Siemens S7 controller. The S7 interface controls the NEXUS XDSP board, which is responsible for positioning and parameterization.


The NEXUS network was installed in the plenary hall in 1999 as a proprietary system and was, at that time, the first in the world with digital microphones. Now it has been replaced 1:1 by a new, modernized system. A special feature of this project is, on the one hand, the many sound reinforcement positions. The number of microphone interfaces is also exceptionally high at 140. They were connected as standard and converted to digital microphones according to AES42 with integrated TrueMatch A/D converters. The NEXUS network was highly customized with extensive logic programming.


"The Bundestag has again chosen NEXUS and a mixing console from STAGETEC - this shows that our technology has met all requirements over the past 18 years. We are very pleased with this special reference," comments André Scheel from STAGETEC, who was responsible for the installation in this project. "The fact that this project, which was under great time pressure, was so successful was also due to the very good cooperation with Siemens and the employees in the Bundestag. This is all the more significant because we don't often work together."


Another special feature of this project is that the cabling was not renewed. Since STAGETEC already networked the NEXUS network with fiber optics 18 years ago, it was not necessary. On the other hand, there was also no time for it, because it had to be taken into account that the Bundestag has to react to daily political topicalities with special sessions. This meant that the plenary hall had to be ready for operation within five days, even in the weeks when there were no sessions - either by reverting to the old system or the new one had to be installed so comprehensively that it would work.


Increased security is achieved by the redundant design of all NEXUS audio modules. Extensive self-testing functions covering all components from the microphone to the loudspeaker ensure rapid diagnosis in the event of a fault.


At the plenary hall, there are two control rooms where AURATUS mixing consoles are installed. The AURATUS in the plenary hall control room is responsible for the parliamentary sound, i.e. for the public address system in the Bundestag. The AURATUS in the broadcast control room is used to play out the signals for the radio and television media, for example for the broadcasts on phoenix, on parliamentary television and internally in the Bundestag. For reasons of space, both AURATUS consoles are special versions consisting of only one fader level and the meterbridge, the multifunctional cassettes are missing. Instead of the central screen, the meterbridge has the monitoring cassette built in.




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