What particular design considerations do outdoor spaces raise? In the first of two features, TFA looks at how the audio systems have been integrated into two football stadiums in the searing heat of Qatar.
Two soccer stadiums in Qatar have each been equipped with a specially designed Renkus-Heinz IC Live digitally beam steerable PA system, configured to deliver music, safety announcements and match commentary in the largely roofless venues, which are owned by the Qatar Olympic Committee (QOC).
The multi-purpose stadium in Al-Rayyan, Qatar, home to the Al-Rayyan and Al-Kharitiyath sports clubs, and the near-identical Al-Gharafa stadium, seat around 25,000 apiece. Both are largely open-air apart from VIP grandstands, and in a country where summertime temperatures can hit 40°C.
They are the latest in a series of high profile Renkus-Heinz beam steering installations in the Middle East, two other recent prestigious projects being the Qatar Royal Mosque and the Dubai Swim Stadium.
Consultant Fredrik Setterberg of Swedish audio specialists Soliflex was called in to fine-tune the design and, he explains, this has turned out to be another world first for the versatile IC Live system, which was installed in record time by local contractor Al-Tamas.
Says Setterberg: “It was a very fast job from start to finish - about a month from the order being received. We and Al-Tamas equipped two stadiums with 16 IC Live arrays and two sub-woofers in each stadium, each connected via RHAON (Renkus-Heinz Audio Operations Network). We originally planned to have the loudspeakers on the edge of the pitch shooting upwards towards the audience, but the QOC asked for a re-design, partly because of visibility issues. The main challenge was to massively improve intelligibility across the seating areas without interfering with sightlines - and without a roof to hang speakers from.”@page_break@
He continues: “We solved it by mounting the IC Live columns on custom-built downward-angled mounting poles on the stadium’s outer wall behind the spectators, with the cabinets upside-down to get the high frequency drivers as close to the audience as possible. A combination of the mechanical angling and IC Live’s beam steering effectively aims the sound directly across the spectators’ heads.
“The solution worked out really well. We have very good STI values, and the SPL is more than enough to cover the whole arena - even with all the crowd noise.”
Where the original PA had employed 42 loudspeakers around the arena, the new solution with IC Live sees just 16 units covering the whole stadium. The CobraNet system has an analog backup for redundancy and the system is designed to allow future expansion of its functionality to include voice alarm capability. “It's only a PA for now, although we have recommended that we can integrate it with the voice alarm in the future, because the IC Live is considerably more powerful than the existing VA loudspeakers, Setterberg explains.”
Sound sources are mostly music, in the shape of national anthems, and spoken commentaries, announcing the names of goal scorers and the recipients of yellow cards, delivered by an announcer from a media booth in the grandstand using a wireless microphone.
A 360 Systems hard-disk-based playout system provides the musical content, with a Yamaha mixer integrating the various sound sources. A MediaMatrix NION NX handles distribution to the system’s 11 zones, which can be switched on and off independently, while all the speaker processing is performed within RHAON.
“The big advantage with RHAON is that you don’t need an expensive DSP processor, because the only function it performs is the matrix zone routing,” says Setterberg. “We use RHAON for EQ and beam steering and everything else, and networking is all on fibre optic with Cat 5 up to the loudspeakers, which are weatherised and are fitted with ruggedised Ethernet switches that will work at up to 85°C without fan cooling.”