Legendary electronic dance act Underworld took to the road in December for a series of arena shows around Europe and at Wembley’s SSE Arena, giving audiences a refreshingly new immersive sound experience courtesy of Clair Global and Astro Spatial Audio.

The initial spark of an idea to expand the band’s live sound into a more immersive landscape came from an Alexandra Palace show in 2017. In an innovation rarely seen at an arena show, Rick Smith performed a support set from front of house, which pulled the focus of the production away from the stage and into the centre of the arena, enhanced by additional hangs of PA down the sides of the room creating an enveloping sound field.

FOH engineer Mark O’Neill recalls how the immersive concept developed from there: “We didn’t have any kind of spatial processing at the time – although there were several systems out there, we didn’t have the time to implement one – but we did succeed in creating more of a club feel even in such a large and impersonal space as Ally Pally. Around that time we started looking at the Astro Spatial Audio system, which coincided with a show we had at the Ushuaia club in Ibiza where there is an installed system. It gave me an insight into what was possible, and I could definitely tell that there were some things Astro was doing to the soundscape that I liked and that I thought would work well for the band.”

Underworld’s go-to PA provider, Clair Global, put a small scale system with Astro Spatial Audio processing into the band’s studio, allowing O’Neill to experiment and develop various ideas that would eventually translate up to large scale venues, and consequently Clair Global’s Andy Walker, together with 2B Heard Director Dave Wooster, ASA’s UK distributor, then agreed to provide a full scale Clair / Astro sound system for December’s arena shows in Europe and at London’s SSE Wembley Arena.

The immersive PA setup for Wembley was a full Clair Cohesion system comprising 16-deep CO-12 main speaker hangs at left and right, and 12-deep CO-12 side hangs outside of those. The high output, three-way CO-12 is Clair’s flagship stadium, arena and large-scale festival system with full frequency response based around dual 12” LF drivers. Flown behind the main hangs were four-deep CP-218 dual 18” self-powered subs for VLF response, with a further 16 CP-218 enclosures configured in a cardioid-steered line on the floor giving directional sub-bass coverage. Six CP-6 self-powered point source enclosures delivered stage lip fill coverage for the nearest audience members.

Two L-shaped trusses enclosing the arena floor supported six hangs of six-deep CO-8 dual 8” line arrays to give surround sound coverage of the arena floor, and six hangs of eight-deep CO-10 formed the delay ring for the bleachers. The system was driven from a total of eight Clair PakRaks positioned under the stage each containing nine Lab.gruppen PLM 20k44 amplifiers, while control of the CP-218 self-powered subs and CP-6 front fills was managed by four Lab.gruppen LM26 system controllers, and a further two LM44s were utilised to take care of the fallback analogue back up.

“Unlike other immersive systems, Astro Spatial Audio really is TRUE object-based audio,” said Wooster. “The SARA II Premium Rendering Engine takes care of the rest. SARA II calculates the position of each audio object in the 3D performance space relative to the loudspeaker framework in real-time and at extremely high resolution – in the simplest terms, an intelligent audio file populated with unique information specific to individual audio objects, such as the gain, the type of source, and spatial position.”

The SARA II Premium Rendering Engine is housed in O’Neill’s rack at front of house and connects directly to the amplifiers via Dante, and there’s also a Dante send straight from the console to the amplifiers which provides two layers: an Astro layer and a non-Astro layer.

O’Neill’s personal interpretation of the Astro Spatial Audio system has led him to settle on a hybrid application as the centrepiece of Underworld’s audio production. “There are two layers,” he explained, “one layer was fed from traditional left, right, sub and front fills sends, and a spatial layer with discrete outputs from the Astro system. This allowed me to get the fundamental mix together and then start to pull aspects in to the spatial mix, and this made it very quick for me to create and manipulate the spatial mix. The speaker system presented the spatial mix in two different ways to give the experience over the whole audience area. The CO-8s are facing into the arena floor and give the spatial image on the arena floor along with the Main L+R CO-12, the CO-10 arrays then face outwards acted initially as a ring delay of the main system, and then there is a layer of the spatial information over the top. I think of this as an inverted spatial image from the inwards firing arrays. It worked very well and I felt it was the most difficult part to overcome in the system design.”

“The Astro aspect of the mix is not rigidly programmed and the way the spatial mix is done I can easily adjust with shortcuts I have on User Keys and Quick Controls of the console. Most of the objects within Astro are static – some are specific sources off my console, and others are driven off aux sends. This keeps programming within the console and gives me freedom with Astro to concentrate on the spatial aspects of the mix. My sends to the Astro positions are recalled in scenes for songs in the console, so that when I recall the next song the spatial mixes change.”

Time spent in band rehearsals and production rehearsals has clearly paid off. “We’ve got very good results with this system, a great combination of the depth of the Astro sound field and the coherence of the Clair PA. The imaging and space left within the mix was impressive. Andy has succeeded in making this system both scalable and tourable. His design for enclosing the arena meant that the floor could be completely within the Astro sphere while the bleachers could still have plenty of movement and feel more involved with the sound experience through the ring delays.”

“The shows we’ve done so far have drawn very positive audience comments,” commented O’Neill. “I never set out for people to notice things swinging around my head – that was never the point, although that sort of thing can have its place within the production. We just wanted every member of the audience to feel like they were in the sound and part of it, not watching a show they could hear coming from the end of the room.

“I’m really happy with what we’ve achieved so far, but there are other ideas that we could explore further. The Astro system is a whole world of possibilities and I can see many different applications for it in the future.

“I think Astro is a fantastic tool,” concluded Walker. “For any kind of dance act this would be the way to go as it has so many possibilities. You can really see how Mark has created his own unique perception for Underworld and made it his own. I love the fact that it’s easily tourable, and the really cool thing about it is the scalability which has allowed us to play in various venues of differing sizes without the need for reprogramming. It’s brilliant!”

About 2B Heard 

2B Heard is a leading UK-based distributor of premium audio brands and is the sole authorised representative of K-array, Astro Spatial Audio, Innosonix and Solid State Logic in the UK and Ireland. Led by respected industry figures Dave Wooster and Sam Nankivell, the company delivers exceptional service and support based on real world experience within the UK’s entertainment technology, professional AV and home audio markets. For more information please visit www.2b-heard.com.