In an attempt to create a natural habitat for its inhabitants and an air of authenticity for its patrons, zoo habitats often resemble tropical rainforests. Hippos and elephants, for example, feel more at home in the heat and humidity of a jungle than the concrete surroundings of a temperate climate. Laying 1-degree north of the equator, Singapore Zoo commands a geographic advantage in which the temperature remains a fairly constant 30-degrees centigrade, with convective rainstorms an almost daily occurrence and high humidity guaranteed. But whilst the animals feel at home and the visitors appreciate mother natures’ backdrop, any A/V technology used to promote the exhibits is going to be severely tested.
Based on an ‘open zoo’ concept, the oppressive cages which typify old zoos are completely absent at Singapore Zoo. Instead, all the animals are kept in spacious, landscaped enclosures, separated from the visitors by dry or wet moats, which are themselves concealed with vegetation or dropped below the line of vision. In an attempt to not only entertain but also educate, several amphitheatres and large exhibits including Creatures of the Night, Splash Safari, The Elephants of Asia and The Rainforest Fights Back have been equipped with more powerful audio solutions over the years.
Audio supervisor Waren has been an employee at the Zoo for some six years and explained that the outdoor speakers required renewal owing to exposure from the constant high humidity, sunlight and rain. ‘The weather here just eats into them in the end,’ he demonstrates, showing a video clip during a severe thunderstorm. The Rainforest Strikes Back show, which hosts a number of marine and aquatic mammals including sea lions, has a partially covered amphitheatre seating area for its shows. The canvas covered fan shaped open area can host over 1,000 visitors for the four 25-minute daily shows that it stages. ‘The previous two-way point source sound system was not weather-proof and it was providing poor coverage. We were receiving many complaints regarding the lack of coverage in the central seats – it was time to install a new sound system.’
AV World Engineering Pte Ltd was contracted by the zoo to design and install a new weather-proof audio system that would provide even coverage across the wide seating area. ‘We opted for the relatively new FBT Shadow 142L line array system,’ explains AV World Engineering’s project manager, Alex Seah. ‘I had heard them in action at an aquatic attraction in Melbourne and was impressed.’ Supplied by distributor Meditec Trader Pte Ltd, AV World Engineering Pte Ltd worked closely with FBT’s pro audio consultant and Powersoft’s application engineer Remo Orsoni to create a design.
Classified with an International Protection Rating of IP55, the Shadow system was launched in 2014 for those applications battling with extreme weather conditions such as the zoo firmly in mind. The prime design consideration in the cabinet’s and its’ internal components is extreme weather resistance. The weather resistant driver is further protected by the water-stop grille, preventing the elements from getting into the enclosure. Creating minimal acoustic attenuation, the protective grille is a three layer structure consisting of a treated external perforated stainless steel panel, a centre layer of reticulated foam and an inner layer of water-repellent polyester mesh. All internal circuitry is protected with a special sealing and treated with weather proofing compound against the effects of moisture, corrosion and oxidation. The loudspeaker cabinet is a single polyethylene, roto-moulded enclosure, which is fully UV protected. The curved shape helps to reduce acoustic reflections and standing waves within the enclosure for improved LF performance, whilst inhibiting standing water and diffracting wind on its exterior. Finally, the suspension stainless steel hardware system and accessories are all weather resistant.
By ensuring that weather-proof speakers keep out the elements, many tend to be compromised in terms of audio performance. However, the Shadow 142L turns out to be quite a musical star in its own right. The 1000W-rated line array speaker system combines a 14-inch woofer with 3-inch voice coil and is capable of producing a maximum SPL of 137dB. The HF section consists of a constant directivity horn loaded to dual 1.4-inch compression drivers with a 2.5-inch coil for smooth, wide dispersion. In fact, the horizontal coverage is a generous 100-degrees, whilst vertically the hardware adjustable angle can be set at either 7.5-degrees or 15-degrees depending on the application.
Working on the design in Italy, Mr Orsoni realised that the venue was perfect for the Shadow system. ‘With Shadow, FBT boasts the only IP55 rated line array in the world, which was critical for the application in mind. However, the full range audio performance of the Shadow142L, with its custom components, providing a wide horizontal coverage, really helped get the coverage required over a wide seated area. Finally, the Zoo management asked for an extreme L-R side install, out of the path of the animals and not to visually impair the attraction. However, when I plotted this in EASE Focus 2, it wasn’t breaking up and the middle seats weren’t experiencing any loss.’
Owing to the zoo’s opening hours, Alex Seah and his team of 10 was restricted to working the night shift over a two week period in December 2014. The team’s first unenviable task was to dismantle the old audio system. ‘We had to remove the corroded speaker and subwoofers that weighed 80kg manually from scaffold towers,’ recalls Mr Seah. ‘Whilst one team was carrying out this task, the other was laying conduits from the speaker positions to the rear control room. Owing to the nature of the venue, one of the conduits is 50m in length and the other is 100m, for which we ran Klotz ais 2.5mm cabling. We really were working against the clock and there were no lights – it was like a jungle at that time of night!’
The 236kg frames combining six per-side Shadow 142L cabinets were hoisted into position and affixed to brackets. Adjacent to these, two smaller 84kg side arrays combining two 142L models serve as the front fills. Customised angled Amphenol weather-proof connectors complete the signal path to the arrays from the control room. The top cabinet in each array has been fixed at 0-degrees to ensure coverage the furthest seats at the rear of the auditorium, whilst the lower four Shadow 142L speakers have each been angled at 7.5-degrees, and the final sixth cabinet, serving as a down-fill, has been set at 15-degrees.
At the end of the installation, Mr Orsoni joined the bleary eyes of the AV World Engineering team to commission the system, completing the task in time. ‘On site, I conducted measurement and analysis with my Smaart 7 set-up and it perfectly confirmed the prediction I had made with Ease Focus 2. System equalisation for the performances have been pre-set into two FBT DLM26 loudspeaker management processors in a unique DCL control, using one input and three outputs in full range, dual dynamic low and high frequency operative modes. Further room equalisations were set using Powersoft’s Armonia Suite software within the two Powersoft X4 four-channel amplifiers.’
Completing the control room suite of equipment needed to host the daily shows, five channels of Shure SLX4 wireless using lapels, handhelds and headsets together with DPA d:fine headsets are stored in a chilled cabinet. Playback is sourced from a pair of Denon DN-4500 players, whilst an Allen & Heath PA20 console is used for mixing the live shows. Mipro MA100SU portable wireless speakers are also deployed when addressing smaller parties without the need for using the full PA system. Technicians Nabil Rahman and Syafa ‘at ‘can easily set up and power down using the Furman CN3600 sequencers, which also provide much needed protection against surges and lightning strikes.
‘Above all else, I’m amazed with the sound quality of the Shadow 142L cabinets,’ concludes Mr Waren. ‘Our overriding criteria of the new system was for weather-proofing and therefore longevity. However, we have acquired much more than that owing to the high-fidelity audio quality and also the even coverage this system provides. The audience in the centre seats can now hear the presenters clearly and those sat in the extreme left and right seats don’t have their sightlines impaired. Previously one of the technicians would have to leave the control room to monitor the system, as we can clearly hear now how even and extremely clear it is.’
Once installed, Mr Seah turned white as a downpour funnelled the rainwaters down the canvas canopy to cascade like waterfalls down both speaker hangs. ‘I just laughed and told him not to worry,’ smiles Mr Orsoni. ‘These speakers can handle everything that is thrown at them and still sound wonderful.’