HOLOPLOT’s X1 system recently provided the audio for The Atmosphere stage for the 20th anniversary of the Tomorrowland Festival of electronic music in the aptly named town of Boom in Belgium.
The spacious Atmosphere stage, which featured a host of well-known DJs, was close to 30m high and 30m wide, meaning it could accommodate up to 5,000 techno fans. The HOLOPLOT system utilised two main arrays consisting of six X1 modules each, with six surrounds of two X1 modules each, at the June festival.
The key challenge to overcome in this installation was the highly reflective surfaces that caused echoes in the listening area, which prevented an even sweet spot to fully benefit from the immersive content played at the stage.
A couple of years earlier, Tomorrowland, together with Noizboyz, had tried to solve the problem by developing a new piece of software which allowed the engineers to upmix stereo signals into multi-channel 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 still proven challenging, with the additional loudspeakers needed to achieve the surround sound effects causing increased reflections and confusion in the diffuse field.
Pieter Doms, sound engineer at Noizboyz and co-founder of stereo upmixing solution Areal, was responsible for the sound design of all 16 stages at Tomorrowland and chose the HOLOPLOT system to improve the audio experience at Atmosphere.
He said: “I was really shocked with the sound quality that was achievable because I expected beamforming to decrease it. 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.”
Doms added that the use of X1 allowed better control of sound, delivering the immersive results of the upmixed content via Areal to the crowd without echoes. The key technologies, he felt, were the two core pillars of HOLOPLOT technology, 3D Audio-Beamforming and Wave Field Synthesis.
Sebastian Boeldt, senior application engineer at HOLOPLOT, commented: “Both allow us to control sound in the 3D space. 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.”
Boeldt addded that HOLOPLOT’s horizontal control allows for the creation of controllable coverage zones, as well as the precise gain and delay alignment between them.
He explained: “This means we can increase the immersive sweet spot and minimise the delay spread, a key parameter when designing immersive systems. 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 a really flexible piece of software that paired beautifully with the X1 system.”
Doms concluded: “The widespread misconception that loud is always better doesn’t apply here, and thanks to the isolated yet aligned zones X1 created and the multi-channel content from the Areal engine we achieved great results. It sounded really tight, giving that small immersive club feeling.”
