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Ducking with ON AIR flex and NEXUS

Geneva, Switzerland, October 2018: In the 25 years since STAGETEC was founded, many a customer has given the impetus for a new product or feature, and STAGETEC was then entrusted with the sound engineering implementation. RTS (Radio Télévision Suisse) had the idea for a simply designed and automated workstation for the most common workflow in sports broadcasts: The 5.1 mix of IT with atmospheres and original sounds from the sporting event and commentary from the announcer's booth. This is a task for which classic audio control rooms are completely oversized in terms of equipment and manpower. Instead of occupying four control rooms and employing four sound engineers, RTS wanted to design a workstation so that one sound engineer could operate four workflows in parallel.

The challenge was that IT varies greatly in volume for different sports, for example, Formula 1 is much louder than tennis. Normally, when mixing, ducking is controlled with a fixed dimming because only one sport is involved. However, when several sports are mixed in parallel, intelligent ducking is needed that takes the sport into account. So an automated adjustment to the IT level with the possibility of manual intervention is needed, because ducking should result in a high-quality sound mix.

In cooperation with BFE, STAGETEC realized an isolated solution for RTS with a connection to a TV control room. The workstation is equipped with four ON AIR flex, two NEXUS base devices and four operating computers with RUI. The mixing consoles were given a structured user interface. Instead of fader and monitor cassettes, two fader cassettes were mounted in a tray. The ON AIR flex each have four faders: two for the commentators, one for the IT, and the fourth fader is used to control the pilot tone rather than the volume of an audio signal, as is usually the case. This can be used to manually intervene during the commentary and determine the ducking depth of the IT signal.

"With the small, user-friendly ON AIR flex, we can centralize the automatic mixing of 4 programs in the same place by a single technician. For us, this is the strength of NEXUS: the centralization and sharing of resources," says Yves-Alain Schneider, head of audio production at RTS.

STAGETEC has implemented RTS's conceptual idea innovatively and efficiently. Especially the new DSP function Multichannel Ducking, where the ducking depth is controlled by the fader of the ON AIR flex, shows the great potential of the NEXUS system. The workflow created here is suitable for all TV stations with sports programming.

About RTS:

Radio Télévision Suisse (RTS) ( is an audiovisual company of the SRG Group that develops its public service programs on four radio channels, two television channels, and several interactive platforms. RTS is headquartered in Geneva and Lausanne and maintains an office in each French-speaking canton, as well as correspondents in Bern, Zurich, Lugano and in capitals abroad.RTS programs are aimed primarily at the Swiss francophone public, who live mainly in what is known as "Suisse Romande," with its 2 million inhabitants. Many RTS television shows, starting with the daily news, are broadcast worldwide on TV5 World. The same is true for the radio programs produced by RTS, which are accessible through its websites in all regions of the world. With an annual budget of 380 million Swiss francs and nearly 1,600 employees, RTS is a leading audiovisual company in its market, both in radio and television. It offers a wide range of programs accessible to all, while respecting its public service mission.


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