How d&b prediction and control contained the boom for Boom.

Held in Portugal every two years since 1998, Boom is one of the world’s best-known transformational festivals, bringing a touch of the alt-eco spirit of Burning Man to Europe. With its spiritual vibe, leave-no-trace environmental ethos and psychedelic visual art, Boom is a focal point for creative energy and environmental consciousness, attracting an audience of forty thousand people.

Thanks to its relatively remote location on the shores of Lake Idanha-a-Nova in the east of the country, Boom has no issues with noise affecting nearby residents. However, it does have its own self-imposed audio challenges. As with all multi-stage festivals, care must be taken that the larger sound systems do not interfere with each other, or with the smaller stages and audience zones. At the same time, Boom’s aesthetic ethos requires that PA hardware blends in as far as possible with the highly decorative, psychedelic stage designs. With these two limitations in mind, there is of course a third requirement – for good quality, powerful sound.

To ensure these requirements are met for all of Boom’s eight stages and zones, the festival organisers employ sound engineer Fernando Rodrigues to look after the site’s sound system designs.

“I’m a long-time d&b audiotechnik user and fan,” says Rodrigues, “and it was a no-brainer to choose the system for the main areas. Actually, not just the main areas - this year we had five of the eight stages using d&b systems, and that was a major upgrade from what the festival had in the past editions.”

Using d&b ArrayCalc to predict the sound for each area and NoizCalc to predict the sound immissions in adjacent zones, Rodrigues specified for the Dance Temple stage a main system of sixteen J8/12 per side, with hangs of six V8/12 as out fills and six J12 as front fills on top of the sub array. For the all-important low frequencies, six J-SUBs were flown per side behind the main PA, complemented by a ground-stacked sub array consisting of thirty two J-SUB and sixteen SL-GSUBs, the ground-stack variant of the new SL-Series. The SL-Series sub components, the SL-GSUB and the flyable SL-SUB, are engineered such that the performance of a single cabinet is an almost exact match for the combined output of a J-SUB and J-INFRA together – a significantly more efficient low frequency solution.

“The flown J-SUBs were positioned behind the PA to reinforce the throw of low end coming from the main hang,” says Rodrigues. “The sub array was thirty two meters long and was initially going to be a combination of J-SUB and J-INFRA. But it was difficult to get the twenty two J-INFRAs that we needed for the two main stages, so the SL-GSUB was a great substitute. With eight stages at the festival, the cardioid pattern of the J-SUB and SL-GSUB was imperative to have. In this way, we manage to control the low frequencies of the system and not disturb the adjacent stages.”

The system covered an area eighty meters wide and sixty meters long. “It was unbelievable how the system performed,” said Rodrigues. “With ArrayProcessing, we could control the level drop depending on the quantity of audience inside the tent. By contrast, outside the tent we had a -20db level drop. In this way we avoided disturbing areas that were not meant to be covered. We managed to deliver sound quality with power inside the tent, but not outside - something never experienced before in this festival.”

The theme for this year’s festival was ‘Sacred Geometry’ and this carried through to the design of the tents. “I ended up with a tent full of huge metal pillars, covered by a mix of fabric and wooden decorations, basically big obstructions for the mid and high frequencies in a certain area, so we used four Y7P as delays where needed. Despite their small size, these are very powerful point source loudspeakers that deliver flawlessly.”

The d&b systems for the two main areas, the Dance Temple and the Alchemy Circle, were provided by Spain-based d&b rental partner, FLUGE. For the Alchemy Circle, a main L/R system of seven J8/12 per side was enhanced with V8/12 out fills and V12 front fills. LF here was provided by a sub array of twelve J-SUB and six SL-GSUBs.

For both stages, the systems were powered by D80 amplifiers – fifty four at the Dance Temple and eighteen for the Alchemy Circle. All seventy two D80 amplifiers were housed inside custom built, air conditioned wooden boxes which kept the amplifiers cool amid temperatures as high as 40˚C, as well as protecting the amplifiers from dust in the daytime and moisture at night. “Thanks to this, we had zero malfunctions due to the heat,” said Rodrigues. Both stages also had foldback provided by M4 wedges, and M2s with J-SUBs used as DJ monitors.

In addition to the systems provided by FLUGE, two Portuguese rental companies supplied d&b systems to Boom zones: Hipnose supplied solutions based around Y8/12s, V-GSUBs and MAX2 monitors for both the Liminal Village, which featured mainly spoken presentations, and the Nataraj Dance Stage. Finally, Audiomatrix provided d&b MAX15, C7 systems as side fill for the Sacred Fire stage and the another C7 system as main PA for the Healing Area.

Rodrigues concludes, “Feedback from the audience was very positive. Sometimes there was disbelief at how it was possible to have the amount of pressure and sound quality everywhere, inside and outside the tent. Even the DJs were asking about the PA system and how it was possible to get this type of result: for them, it is not normal to have this type of distribution and powerful sound all over the audience area, in comparison to what they experience in other big festivals that they play. That is the best feedback that we can get - a DJ that plays in the biggest festivals of this kind, all over the world, saying that he never had an experience like this, ever. This makes all the work worthwhile, and supports our choice of d&b audiotechnik systems.”