Architectural Audio

34 REPORT: ARCHITECTURAL AUDIO

GUILDFORD CATHEDRAL

COMPANY: K-ARRAY LOCATION: GUILDFORD, UK

A visually minimalist K-array loudspeaker system from the Italian manufacturer has been installed at Guildford Cathedral, as part of a major upgrade of its audio systems. Supplied and installed by DM Music, the Vyper ultra-flat line arrays deliver exceptional intelligibility from the discreet, colour-matched enclosures. Guildford’s Grade II Cathedral occupies a commanding position on Stag Hill, overlooking the town and its university. Designed by British architect, Edward Maufe, it is one of the UK’s more modern worship spaces and one of only three built in the 20th Century. Construction started in 1936, but was halted by the outbreak of war and only resumed in 1954. Towards the end of 2017m the cathedral’s technical staff decided to replace the outdated 100V line loudspeaker system that was no longer up to the task.

The team approached Harpenden-based DM Music, one of the UK’s most experienced specialist church systems integrators, to tender for the audio design project. As part of the upgrade, it was also necessary, from a health and safety perspective, to remove the asbestos-based acoustic plaster that was lining the 22-metre high, 1,000 sq metres ceiling - and, as a result, the building acoustics presented the installer with a sizeable challenge. DM Music’s Installations Director, Graham Bennewith, explained that removing the plaster made things substantially worse, so he had to design a loudspeaker system that would be intelligible, even with a subsequent RT60 reverb time of around 6.5 seconds. “As well as presenting a difficult acoustic environment, like many of our Grade I and Grade II listed churches, aesthetics was also a major consideration.

The advantage that K-array has over other loudspeaker manufacturers is that not only do its installed products sound great in an environment such as this, they are also very discreet, and we were able to RAL colour-match to the stone work to make them virtually invisible,” Graham said. The Vyper KV50 column arrays installed in the nave consist of eight closely-spaced one-inch drivers in an elegant stainless-steel chassis, providing focussed listening from the inward-facing pillar locations. Their narrow vertical dispersion and wide horizontal coverage pattern ensure that sound is directed solely at the congregation and away from reflective surfaces. In addition to the 16 KV50’s covering the whole of the nave, eight KU44 colour-matched subwoofers are fixed on the outside of every other pillar, complementing the mid-high loudspeakers to provide

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35 REPORT: ARCHITECTURAL AUDIO

full range frequency response. In the crossing, a pair of KV50’s point back towards the choir to fill in for the front few rows. Tornado KT2 spot monitors are installed under the choir pews. This location is also the control point for the whole system - equipped with a fixed iPad, a mobile iPad so the vergers can walk around and assess sound quality, a CD player, and a recorder. An additional pair of KV50 loudspeakers fire up towards the presbytery. “The cathedral is used quite extensively by the University of Surrey, and it has a lot of concerts in here,” commented Graham. “For a graduation ceremony, for instance, it will bring in a video that’s been designed for a full range system, so the subwoofers enable us to give full range response. For speech the subwoofers aren’t essential but they do add a bit of presence at the bottom end.”

He continued: “To complete the loudspeaker setup, there is another pair of KV50’s with KU44 subwoofers projecting sound to the high altar. We’ve also installed a feed into the choristers’ practice space to allow them to hear what’s going on while they’re getting ready, while in the West Porch we’ve got KT2’s to provide some in-fill, and in the West Gallery we’ve also installed KV50’s.” “At the heart of the system are two Dante-enabled Yamaha MTX5D processors - one in the loft and one in the basement. Everything in the East End all wires down to the basement, which is then linked on Dante to the processor up at the top, all through 10mm conduit. Radio mic receivers are up in the top, and from the MTX5D we feed to the K-array amplifiers, which are mostly KA24’s,” he enthused. “The choice of K-array was a simple one. Every year we look for loudspeaker brands, we go to the

tradeshows and talk to as many manufacturers as we can. We did consider larger steerable arrays for this project, but the result is not as aesthetically pleasing. In terms of matching the building, K-array is really the only brand that can do the job.” “So far, we’ve had some very good feedback,” concluded Graham. “Our contract included one year of technical support and that means regular tweaks, so I regularly meet with members of the church to work out if there’s any dead spots, and fine tune all the delays and settings to their exact requirements. They’ve asked for some zones to be slightly louder and some to be slightly quieter. We plotted it completely flat, so we could we have a bit more in this area and a bit less in this area, and that’s down to their personal preference.”

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