Derby County's bold decision to replace ageing PA kit with a whole new sound system may pay dividends by generating new revenue - sweet music to the football club's investors.

By Mike Lethby

Towards the end of the 2003-4 season, the board of directors of Derby County Football Club, in the English football championship league, faced an unpalatable, if not entirely unexpected, decision. The club’s public address system, installed in 1997, was approaching the end of its useable life and would have to be replaced..

Having bitten the bullet, the club now finds itself the proud owner of one of the most sophisticated multi-purpose stadium audio systems in the UK, if not the world. It’s the first of its kind with an all-digital CobraNet-based infrastructure featuring full redundancy, self-powered loudspeakers and much more besides – a system whose versatility offers the club considerable commercial potential.

"The decision was forced on us by a combination of circumstances,” explains Financial Director Andrew Mackenzie, “but the board decided not to do it by halves but to approach it as an opportunity to create a solution that would benefit the club, as well as providing the essential safety systems for fans, players and staff.”

1997 was the year the club made its move from the historic but ageing Baseball Ground to the brand new Pride Park stadium, sited in a retail park on the north-eastern edge of the city. Its sound system was installed by subcontractors as part of the new stadium’s design and build contract.

“The original system was used for music and everything else,” continues Mackenzie, “but after a few years we reached a point where replacement parts were becoming hard to obtain. We were aware, as everything was tested and certified every year before the start of the season, that it was getting closer and closer to the end of its operating life. When it finally failed intelligibility testing in various areas it became obvious that we needed a brand new system for the whole building.”

With a full voice evacuation system as the imperative, the board sat down to consider how to add commercial opportunities to a state-of-the-art operational safety system. Pride Park’s complex of hospitality suites and bars immediately suggested themselves as potential extensions to a multi-purpose system that could relay high quality music, commercials and promotional content as well as the usual matchday information and exhortations to move badly parked cars.

Derby’s safety facilities manager Chris Parsons observes: “We are the biggest commercial operation in the whole of Derby, with the capability to stage dinners, dances, marriages, boxing matches and even pop concerts, with permission for 8,000 people on the pitch.”

With objectives established, the design and installation project was put out to tender, a process that led to the appointment in 2004 of system integrators Marquee Audio, who elected to work with pro audio distributors Beyerdynamic UK. The latter’s brand portfolio includes the Renkus-Heinz self-powered loudspeakers chosen for the project and numerous other professional audio marques.

Marquee Audio’s managing director, Spencer Brooks, explains: “Having been invited to tender we proposed a fully-featured system with complete redundancy which would embrace the latest technology — seamlessly integrating with the club’s existing infrastructure yet at the same time extending its scope into the corporate areas and ground control.”

Beyerdynamic technical director Jon Stanley devised a technical design concept which, in terms of practicality, could be delivered as an integrated, usable and compliant system. Working in conjunction with Stanley, Marquee Audio’s Scott Wakelin project-managed the installation of a fully IP-addressable, multiple-zoned, fully-monitored, A + B redundant system — both inside the grandstand of the 30,000-seat bowl as well as the general concourse, season ticket holder/executive boxes and five function suites — all with independent source and volume controls.

The installation complies with the standards set out in BS5839, BS7827, BS EN 60849 and BS 7671 – mandatory for voice evacuation and public evacuation – and exceeds the desired RASTI (Rapid Speech Transmission Index), STI scores and SPL requirements for systems of this type. The PA system also conforms to the Green Guide to Safety at Sports Grounds.

The major installation work was carried out during November and December 2004 when speaker clusters were flown under the canopy rim, using a pair of cherry pickers, at a height of 27 metres. “During this time the engineers endured wind, rain, hail, sleet and even snow — not to mention the shortened daylight hours — to deliver the system in time for the Boxing Day to New Year calendar of first and reserve team games,” recalls Wakelin. At the same time the stadium was fitted with an upgraded fire detection system.

Breaking from traditional stadium sound system design, the architecture is based around CobraNet audio distribution over CAT5 cabling to each of 44 active Renkus-Heinz ST4 HO loudspeakers in the main bowl — making Derby the first stadium to use weatherised self-powered cabinets in an outside environment.

The weatherproof speaker cabinets, configured in pairs and mounted on purlines to generate maximum dispersion, each include their own D-class amplifier (with built-in R-Control monitoring network facilities) — providing maximum efficiency and power consumption. Since the long cable runs (and thus power loss) between the amplifier rooms and loudspeakers found in conventional analogue systems are eliminated, there is a tangible benefit in power savings for the stadium.

The ST4 HO (High Output) loudspeaker, besides its digital connectivity and integral amplifiers, offered a number of extra technical advances (including a unique Quad-8 doublet design and a CoEntrant high frequency transducer) which combine to produce highly directional output as well as high quality sound. The ‘HO’ version was custom-built for the project by Renkus-Heinz to yield an extra 4dB of power compared to the standard model.

“Having a premium self-powered product such as the ST4 offered us both technical and practical advantages, and obviated the need for miles of copper cable running through the grandstand roof,” explains Spencer. In addition, Renkus-Heinz provided the EASE acoustic analysis that assisted Marquee in meeting the project’s demanding technical specifications and standards.

Local engineering company Robinsons Construction fabricated the bespoke loudspeaker yokes, which ensure the correct alignment of each ST4 cluster in accordance with coverage angles determined by EASE acoustic analysis. Each cluster is aligned to provide coverage from pitch level to the top row of the grandstand.

Two miles of fibre optic cabling form the fibre optic backbone of the project, connecting the five different rack positions around the ground with three independent fibre rings, two CobraNet A + B and an IP — plus additional rings for redundancy.

The network also allows remote system diagnostics and health checking offsite. The club can carry out system diagnostics and print fault record logs as required, while Marquee’s technicians can monitor performance from their south-west London offices over an ISDN line.

Biamp’s CobraNet Audia Flex processing and matrixing platform, another brand handled by Beyerdynamic UK, distributes prioritised audio feeds to each zone in the system and provides all the processing, matrixing, routing and priority control. The latest CUE touch screen control system manages and monitors all aspects of the system.

Each of five independent rack locations has the new TouchCUE-S /R rack mount touch panel to display and relay system fault messages in the event of an incident, while two MonitorCUE-V master touch screens, in the Match Control Room and the Security Room for zonal and maintenance paging on match day, are linked to Beyerdynamic MTS67 microphones to ensure the correct messages are heard in each zone.

To cater for a fire or other emergency event, a Prodytel output box automatically distributes pre-recorded voice evacuation messages, stored as WAV digital audio files, to all concourses, hospitality areas, corridors and the main bowl.

Marquee Audio also integrated part of the existing 100v line system which operates outside the bowl. Powered by ten Bittner eight-channel amplifiers, every speaker is monitored by the Klein and Hummel DLC impedance line controller. Should any speaker fail, staff are immediately notified by audible alarms and via the CUE touch screens throughout the stadium.

To cater for entertainment and hospitality applications, inputs are provided for Derby County’s existing DJ and background CD system (as well as ancillary mixing equipment), while in the Assa and Toyota Suites, as well as the Business Club, custom facility panels’ inputs ensure that each room can operate independently for corporate events and conferences. This, in turn, will generate additional revenue for the club.

The system’s power supply is backed up by a battery-operated UPS in the event of power failure. This would power the system for 15 seconds while the back-up generator settles into stable current delivery.

As the final step, independent acoustics consultant Richard Northwood of consultants COMS carried out the final compliance testing, RASTI testing and provided additional custom software and hardware interfacing.

Martin Smith adds: “Since we can send different audio signals to different areas of the stadium, on match days we can now broadcast information and advertising on the outside of the stadium. It also means that corporate hospitality can use the locally-provided inputs for their guest speakers in each of the three main lounges, and finally that the DJ can play to the stadium crowd and hopefully build up a fantastic atmosphere. In the meantime we are continuing to learn about the PA system’s ability, and experimenting with what it can do for the club.”

The system has been warmly received by the stadium’s management and maintenance staff. Martin Smith says: “Marquee Audio have been very professional and a joy to work alongside. Their commitment to their work is admirable and their workforce very knowledgeable.”

Jon Stanley adds: “Beyerdynamic’s design concept met the criteria for cutting-edge, high quality audio and a highly advanced VA system, and Marquee Audio took the project from its design stage and provided the engineering resource to deliver a fully integrated system, installing and configuring it magnificently. Working in partnership, and sharing our specialist knowledge, we have a cost-effective system that outperforms any of similar calibre, and Marquee have implemented Beyerdynamic’s most advanced voice alarm sound system in Europe.” Scott Wakelin also paid credit to Marquee Audio’s engineers Martin Bonsoir, Patrick Roach and Alistair Dixon, who worked tirelessly to ensure the deadline was met.

Derby County’s Chris Parsons concludes: “In order to increase our opportunities a completely new system was essential — if we had attempted to salvage part of the original system we would have ended up with a mish-mash. We know we have a great system and are only beginning to find out its full capabilities. I’d be happy to show this off to any club.”