Now in its 20th year, the Tomorrowland festival continues to celebrate all genres of electronic music at its home in Boom, Belgium. This year, Holoplot’s X1 system was provided the sound for The Atmosphere stage, a custom-made circus-top tent featuring DJs Amber Broos, Dyen, Ellen Allien, Olympe and Adam Beyer. At close to 30m high and 30m wide, it can accommodate up to 5,000 fans using two main arrays of six Holoplot X1 modules each, with six surrounds of two X1 modules.
The key challenge was presented by highly reflective surfaces in the audience area. Pieter Doms – sound engineer at Noizboyz and co-founder of stereo upmixing solution Areal – was responsible for the sound design of all 16 festival stages and chose the Holoplot system to improve the experience at Atmosphere.
‘I was really shocked with the sound quality that was achievable because I expected beamforming to decrease it,’ he says. ‘It sounds great; almost studio monitor clean. It’s amazing how the quality rises when you just focus audio on the people and don’t create any reflections. You get a very clean sound, and that improves the immersive experience. It gives you that small club feeling, but you’re in a ginormous tent.’
The festival focuses on continually evolving, actively developing and seeking new technologies to push the bar for its music experiences. For Doms, Holoplot was the next step to improve the audio at Atmosphere and enhance the immersive feel of the stage.
In the spirit of technological advancement, Tomorrowland, together with Noizboyz, had already developed new software to upmix stereo signals into multichannel content in real time. This had been used at Atmosphere for a couple of years already, but the size of the tent and the required distributed system had proven challenging for the designers in the past, with the additional loudspeakers needed to achieve the surround sound effects causing increased reflections and confusion in the diffuse field. Using X1 allows better control of sound, delivering the immersive results of the upmixed content via Areal to the crowd without echos.
Enabling this are the two core pillars of Holoplot technology, 3D Audio-Beamforming and Wave Field Synthesis. ‘Both allow us to control sound in the 3D space,’ says Holoplot Senior Application Engineer, Sebastian Boeldt. ‘We can precisely shape the coverage areas in the audience zone, but also avoid certain shapes of the venue, minimising reflections and improving the clarity of the performance.’
Holoplot’s horizontal control not only allows for the creation of controllable coverage zones, but also the gain and delay alignment between them. ‘This means we can increase the immersive sweet spot and minimise the delay spread, a key parameter when designing immersive systems,’ Boeldt explains. ‘The combination of sound control via avoidance of the tent surfaces and division of the crowd into time aligned coverage zones create a perfect base canvas for the Areal technology to shine. It’s really flexible software that paired beautifully with the X1 system.’
‘The widespread misconception that loud is always better doesn’t apply here, and thanks to the isolated yet aligned zones X1 created and the multichannel content from the Areal engine we achieved great results,’ Doms reports. ‘It sounded really tight, giving that small immersive club feeling.’
