Festival of Life

All-night prayer event with d&b

Established in Nigeria in 1952, the Redeemed Christian Church of God is a fast-growing church with thousands of parishes in over 150 countries, of which circa 670 in the United Kingdom. As the number of parishioners booms, so does the number of people who attend the bi-annual ‘Festival of Life’: an all-night program of prayer, praise and worship that has been organized in the UK since 1996.

No fewer than 40,000 people attended the events at the London ExCeL Exhibition Centre. As the Church considers it a priority to involve every single attendee in the worship and prayers, it was willing to invest heavily in a top-notch AV solution. SFL Group, one of the UK’s leading AV experts, was contracted to manage the technical production, which included sound, lighting and video systems.

The Excel centre (North Halls) is a huge space. This may be the biggest indoor area in the UK. The stage placement in the hall meant that 40,000 seats would be laid out in an area 275M long by 80M wide, a daunting proposition for any sound designer.

The system was designed to make sure the engineers has 10dB of system headroom above the maximum required dB(A) SPL for the event and that there was no more than a 6dB level change from the loudest point in the venue to any other point.

By designing to this criteria SFL were able to ensure that all members of the congregation are at the “same event” in an audio sense. As this was to be a contemporary gospel worship event, the SPL level capability would need to be around 98dB(A), the system was therefore designed to be capable of 108db(A)  to meet the criteria.

Planning a solution like this starts by looking at the space. During the site visit we identified obvious challenges in the room acoustics that we subsequently addressed by way of venue draping and baffles provided as part of an holistic audio solution.

Using a mixture of computer tools the system included venue CAD plans, Smaart Acoustic Tools for measuring RT60 (reverb times), and d&b audiotechnik Array Calc for the Q1 speaker systems chosen.

For this event SFL heavily relied on the d&b R1 Remote Network software allowing them to preconfigure and control all amplifier functions from a central and wireless location. The speaker system would end up with 56 channels of amplification driving over 100 speakers distributed around the hall in various “amp farms”.

In such a huge distributed system SFL needed to be able to test, time align and calibrate in a systematic and centralised way. d&b R1 works flawlessly for this.

The system design was realised using multiple time aligned drops of d&b Q1 line array. In total there were 21 independent hangs of Q1 and Q-Sub. The basic approach was to exactly divide the venue into equal sized “chunks” being energised by their own high powered speaker systems. As a result, the sound at the back was exactly the same as the sound at the front!

For this event the FOH desk was a digital Yamaha PM5D feeding signals to the d&b digital/DSP D12 amplifiers.  To ensure the highest possible sound quality a digital audio distribution system was designed that allowed AES/EBU to be transported well over its specified 100M maximum. This was an absolute necessity for this event as the  rear amp farm was 225M away from the FOH mix position.