An events space adjacent to the new penthouse suites at Battersea Power Station in London saw Rossco (based in Herfordshire) overcome a unique challenge by utilizing older Martin Audio technology to deliver quality reinforcement while minimizing the impact of sound on the surrounding environment.
As part of the Grade II-listed building’s regeneration project, it was stipulated that a new tower had to be erected to replace the original iconic chimneys, the natural habitat to a breeding pair of peregrine falcons who have been nesting there for 13 years. Rossco was introduced to the project by Simon Woodward of Polar Bear Live at the inception. As an acoustics consultant and event technical provider, MD Ross Sharples has provided audio support since the original confirmation of the Malaysian Consortium bid back in 2013.
“We are fully qualified when considering the impact of sound on the environment,” Sharples notes. And this includes the falcons’ well being, where a 1-min calibrated measurement mic has been placed near the nesting platform to monitor any sound disturbance.
The venue’s operators, the Battersea Power Station Development Company, started to introduce events on the jetty overlooking the Thames last summer. An over-the-top line array was brought in by another service provider with the result that the sound traveled across the Thames to Pimlico and beyond.
“Everyone complained and that jeopardized the license,” reports Sharples. “So this year they brought Simon back and he commissioned us to achieve more acceptable levels.”
The coverage distance needed to be half of the 100-meter long (10-meter wide) jetty, with a 5 x 3-meter hi-res LED screen at one end and a front of house platform set 45 meters back at the rear. Rossco set a nominal 90 dB(A) sound threshold for the range of cinematic, theatrical and music productions that would take place.
“While the local council [London Borough of Wandsworth] didn’t impose specific criteria, they simply said they couldn’t be exposed to that level of complaint again,” Sharples says. “As I didn’t want to set hard limiters a subjective common-sense approach was called for.”
Rossco installed a calibrated measurement meter that records audio levels as a WAV file. “This is stored as data, so as regards sound levels we can access remotely and ensure its within permissible limits,” he says. To fulfill his objectives, he turned to a pair of Wavefront W2s, stage left and right, with seven pairs of miniature W0.5 running back on either side, spaced three meters apart.
“All are individually time-aligned and EQ’d, pointing inwards and downwards to maintain a stereo image,” he explains. “With a distributed system we knew we could minimize spillage.”
The bigger conundrum was with the subwoofers. “We needed rear rejection as LF would be travelling backwards towards the falcons’ nest, and that was the primary concern. A cardioid array would have spoiled the aesthetic.” The approach is a pair of SXC118 subs, into which the W2’s are pole-mounted. “We didn’t need big subs and knew about the excellent rear rejection qualities of this speaker.”
The SXC118 has an 18-inch forward-facing driver and a 14-inch rear-facing driver, each driven independently by separate amplifier channels and DSP. Offering a cardioid dispersion pattern, it combines higher output capability with stated 28 dB rear rejection at 75 Hz.
Sharples confirms that Rossco’s older Wavefront stock has helped meet the objectives of the project: “In fact, visiting sound engineers were saying the sound produced by the Wavefronts was the best they had heard.
“At the same time we’ve done our bit to help protect the falcons — it’s special.”