6K United! – Choral Experience on Tour with zactrack SMART

From the classroom to the big stage – 6K UNITED! makes this dream a reality.

Every year, the project creators organize huge choral concerts with around 6,000 schoolchildren filling the largest halls on a tour across Germany. 6K United Plays in 2024! Eight performances in six cities (Berlin, Hamburg, Düsseldorf, Munich, Mannheim and Hanover), including choirmasters, singing coaches and a 17-piece live orchestra. In 6K United! the hall becomes a stage – and requires a sophisticated sound system concept that takes over the tasks of monitoring the choirs in the stands and provides an ideal location for the audience. For this purpose, Melodus GmbH, as the provider of public technical services, relied on a combination of classic matrix stereo sound and immersive front-fill sound, combined with the zactrack SMART tracking system.

While the choirs, including the vocal coach on stage, were heavily panned to the left and right of the stereo panorama and thus reproduced with corresponding clarity via the DAS Audio stereo system, Melodos had to find an alternative way to have the near-field sound system in the front rows of the audience to ensure the correct positioning: “In a classic front-fill setup, you usually have two options: either switch all the speakers to mono or switch them left and right,” explains Oliver Choteau, Melodos’s director and FOH engineer for the 6K UNITED! Journey. “While in mono no stereo image is created at all, the second alternative causes the stereo image to change depending on the seating position and is distorted.”

Immersive audio tracking

The solution: Melodus integrated the eleven front speakers into the speaker bar via the CODA SPACE HUB immersive audio processor and automatically positioned the sound objects on two 3D audio axes (X/width and Y/depth). “By combining tracking and immersive audio, the image of the coaches and the acoustic instruments works very well in the front rows of the audience,” confirms Oliver Choteau.

Melodus used zactrack SMART for the 6K UNITED! tour for the first time in the sound sector. Ingrid Kreutzer from Melodus was responsible for setting up the system in the changing arenas: “We used eleven anchors, most of which were permanently fixed to the line arrays on the lower array element and remained fixed to the dollies during transport.” 6K UNITED! used nine arrays in the hall – five for monitoring the choirs around the stage and four arrays for the audience sound system. “So we were able to get the system up and running very quickly in each new hall.”

Perfect coexistence: zactrack and grandMA3 for precise light tracking

In addition to the sound tracking, the zactrack signals were also used to illuminate the next point of the musical director Professor Fabian Sennholz and the vocal coaches Lena and Perry, so that they could be perfectly seen by the thousands of choir children in the hall at all times. For this purpose, in addition to the OSC signals for the sound, the pan/tilt values ​​of the moving lights calculated in zactrack SMART were sent to the lighting system via the sACN. “It was plug and play everywhere,” emphasizes Boris Kayser, who was responsible for the lighting design and operation of the full-size GrandMA3. In the end, a total of eight moving lights were operated to track the three people on stage. Kayser retained full control of all fixtures at all times via the grandMA3 interface and was able to operate his signals with or without tracking using separate zactrack fixtures. In addition to the full-size grandMA3, two grandMA3 M processing units were used for additional power and parameters, and the grandMA3 light was also available as a backup control unit.