The second phase of The All England Lawn Tennis Club’s three-year plan to transform the Centre Court at Wimbledon includes the installation of a major public address system.
After going roofless in 2007, Centre Court has assumed a more traditional look following the installation of the permanent non-moveable new roof. At the same time the seating capacity will increase by 1200 to 15,000, and the East and North stands have been equipped with upgraded leisure facilities.
The dilemma facing Jon Berry from RG Jones Sound Engineering, the All England Club’s long-term pro audio contractors, was in finding a system that could be installed on a temporary basis for this year’s Championships, knowing that immediately after the event it would need to be removed in preparation for the third phase. A soffit will be added to the underside of the grandstand along with new roof trusses, to enable a retractable roof to be added in time for the 2009 Championships (along with more comfortable seating). This will be complete with a moving, sliding section, carried on ten trusses.
Much of the preparation work took place before last year’s Championships, but nonetheless it has been a long road — extending back nearly three years — that eventually led Jon Berry to his preferred solution … a purpose-designed AM Series Stadium system from Martin Audio.
In conjunction with engineering consultants several different approaches were considered, including several hundred ceiling speakers and a ring of traditional, horn-loaded public address enclosures.
“We approached a number of different manufacturers,” reveals RG Jones’ sales and installation dept manager. “The constraint we were working under was the requirement that all speakers had to be located in the fixed part of the roof and provide even coverage throughout, without feedback from the Umpire’s mic and presentation mics.” But there is so much air conditioning ductwork carried in the roof that this proved difficult.
Other options included mounting a speaker behind a throat to create a flush-mounted horn flare-style design. “But there were frequency response issues with the flush-mount design so we persuaded the Club to adopt a surface element approach. And of all the manufacturers Martin Audio came back with the best and most well-supported solution.
“Although we had to work hard to persuade the consultants, everyone sensed this was the best, and most cost-effective solution.”
RG Jones already had proof of pedigree since they run both the Martin Synco system and the manufacturers’ own proprietary (W8LC and W8LM) line array systems in their hire fleet, and have installation experience of the AQ Architectural series. They knew they could depend on 100% back-up from the High Wycombe-based company, as well as modeling data from Martin Audio’s EASE expert, Peter Child.
“The original consultant’s spec had multiple rings of ceiling speakers utilising five different models which would have entailed high installation costs” said Peter Child. “After studying the venue drawings I proposed a simpler and easier to install system, utilising front and rear facing AM10 loudspeakers which offered uniform coverage and good intelligibility.”
The company thus requisitioned 71 of the AM10’s, which have been specifically designed for use in stadiums and arenas where high SPL and weather resistance are critical.
The vertical trapezoid AM10 is horizontally-formatted to reduce sightline obstruction. Housed inside the weatherproof enclosure is a 300W 10in (250mm) LF driver coupled with a 1in (25mm) exit HF compression driver mounted on a rotatable 90° horizontal x 50° vertical constant directivity horn.
The speakers are driven by 12 x QSC ISA 800Ti 100V line amps and split into 24 four-wire speaker circuits. In time, RG Jones plan to implement separate line monitoring as part of a full PA/VA system.
However, due to the large amount of ducting, there was little free space in which to operate — and thus the EASE plot had to be remodelled several times to gain the best position options available.
A further prerequisite was that the system not only had to be to weather-proofed but custom coloured to blend in with the roof soffit — thus the company has modified its standard AM10 finish to either BS12B25 spruce green or RAL 7009 green grey. They have applied a special uprated weatherproof varnish and issued a warranty.
Meanwhile RG Jones commissioned custom bracketry from local fabrication company, Bobak Engineering, made up in the same colours and fixed in temporary positions which loosely conform to Peter Child’s EASE plot.
“The design of this bracket allows us to clamp the speaker, yoke style to the sides, allowing us to angle and tilt the speakers accordingly and then lock them off to a fixed angle with a separate bolt,” says Jon Berry. “This is a very good speaker and we are very happy with the result.” Despite the temporary nature of the installation the coverage, he says, is even throughout the Bowl with no sign of any hotspotting or drop-outs.
The PA in the bowl will relay the paging calls as well as a mix of sources. These include the umpire’s microphone, courtside radio microphones and wet weather microphones, and other virtually routed sources. “We can route any input we receive from the BBC or other providers, using our Soundweb system, into the court mix,” explains Jon Berry. “Although we no longer have a ‘Cyclops’ line beep due to the Hawk-eye line call system, we now have audio sources that are required to accompany the VT and flash interviews shown on the new active video scoreboards.”
The specification had called for a full music-rated system (although it will hardly be used as such). “Via the Soundweb DSP we have dynamics and EQ on every input (comp, limiters, parametric and gain), while on every output there’s parametric EQ, limiting, delay and routing — this allows us to transmit test signals during the Championships, so we always know what to expect.”
Now that the 2008 Championships are over the system will be temporarily removed as work begins in preparation for 2009; the next time the AM system is installed it will be on a permanent basis — fixed to Centre Court’s brand new soffit, which will extend right to the edge of the roof’s underside, enabling all the AM10’s to be positioned as determined in the EASE model.