International. The iconic festival celebrating all genres of electronic music, now in its 20th year, was held in the Belgian town of Boom, which bears its name. This year, HOLOPLOT's X1 system was chosen to provide the sound for The Atmosphere stage, a custom-made circus tent that will feature DJs such as Amber Broos, Dyen, Ellen Allien, Olympe, Adam Beyer and others.
At almost 30 m high and 30 m wide, it can accommodate up to five thousand techno fans. The system uses two main arrays consisting of six X1 modules each, with six envelopes of two X1 modules each.
The main challenges that had to be overcome were the highly reflective surfaces that caused echoes in the listening area, which prevented there from being a uniform sweet spot to make the most of the immersive content played on stage. Pieter Doms, sound engineer at Noizboyz and co-founder of the Areal stereo mixing solution, is responsible for the sound design of Tomorrowland's 16 stages and chose the HOLOPLOT system to enhance the audio experience in Atmosphere.
"I was very surprised by the sound quality that could be achieved because I was hoping that beamforming would reduce it," he says. "It sounds great, almost clean like a studio monitor. It's amazing how the quality increases when you only focus the audio on people and don't create reflections. You get a very clean sound and that enhances the immersive experience. It gives you that feeling of a small club, but you're in a giant tent."
The festival is in its twentieth year, a huge milestone for the event. It focuses on continuously evolving, actively developing, and seeking new technologies to exceed the standard of your musical experiences. For Doms, HOLOPLOT was the obvious next step in improving the audio in Atmosphere and enhancing the immersive feel of the stage.
In the spirit of technological advancements, Tomorrowland, together with Noizboyz, had already developed new software that allowed them to mix stereo signals into multi-channel content in real-time. This software had already been used in Atmosphere for a couple of years, but the size of the tent and the distributed system required had still proved a challenge for designers in the past, as the additional speakers needed to achieve the surround sound effects caused greater reflections and confusion in the diffuse field. The use of X1 allows for better control of the sound, allowing the immersive results of content mixed through Areal to be delivered to the crowd without echoes.
The two fundamental pillars of HOLOPLOT technology are used for this purpose, 3D audio beamforming and wave field synthesis. "Both allow us to control sound in 3D space," says Sebastian Boeldt, Senior Application Engineer at HOLOPLOT. "We can precisely shape the coverage areas in the audience area, but also avoid certain shapes of the venue, which minimizes reflections and improves the clarity of the performance."
HOLOPLOT's horizontal control not only allows for the creation of controllable coverage zones, but also for the precise alignment of gain and delay between them.
"This means we can increase the optimal dive point and minimize delay propagation, a key parameter when designing immersive systems," Boeldt explains. "The combination of sound control by avoiding tent surfaces and dividing the crowd into time-aligned coverage zones creates a perfect foundation for Areal technology to shine. It's really flexible software that blended seamlessly with the X1 system."
"The common misconception that volume is always better doesn't apply here, and thanks to the isolated but aligned zones created by X1 and the multi-channel content of the Areal engine, we achieved great results. It sounded very tight, giving that feeling of a small and immersive club," concludes Doms.
