Auckland International Airport, the largest and busiest airport in New Zealand, recently extended its international baggage hall, with Auckland systems integrator Bartons Sound Systems installing a sound reinforcement system for the new space that employs Harman’s JBL Intellivox DC280 digitally steerable, self-powered loudspeaker arrays.
“Until this project, nearly all of the PA loudspeakers used at Auckland International Airport were ceiling speakers or old-style PA horns for exterior areas,” says Rob Waddell of Bartons Sound Systems. “Aside from the fact that we wanted to install something much better, the open-ceiling arrangement of the new baggage area precluded the use of ceiling speakers.”
Waddell adds that installing a distributed system of conventional, cabinet-type loudspeakers and the cable to wire all of them up would not be cost effective.
Before construction even started, it was predicted that based on the architectural plans, the space would be highly reverberant. A further complication: the degree of absorbency (alpha) of the horizontally mounted ceiling baffles that would be installed for reverberation control was unknown.
Waddell decided that a beam-steerable loudspeaker would provide the solution and determined the JBL Intellivox DC280 was the right choice for delivering intelligible sound at the volumes required to handle the ambient noise level of a baggage claim area. The loudspeakers also needed to overcome the high reverberation times created by the space’s open architecture, ceiling beams, walls and uncarpeted floors.
The JBL DC280’s digital beam steering enables its vertical dispersion to be precisely focused and shaped by controlling the relative phase and amplitude of its 16 custom-designed 4-inch drivers and optimizing its volume, parametric EQ and delay using proprietary DSP techniques.
Waddell utilized EASE AURA acoustic modelling software to determine that only two DC280 loudspeakers would be needed to provide clear, intelligible coverage of the new baggage claim area. The loudspeakers are installed vertically along the wall where the baggage belt is located. “Because the DC280 is only 5.3 inches wide, you really have to look hard to realize the speakers are even there,” he adds.
The loudspeakers had to deliver a STIPA (Speech Transmission Index Public Address) of at least 0.5 because the installation serves both as PA and as an EWIS Emergency Warning and Information System. “Management wanted the PA to deliver at least 0.6 minimum STIPA and the JBL DC280 easily achieves this,” Waddell points out. “The DC280’s ability to provide highly focused coverage, yet over a large distance, is key in achieving this level of power and intelligibility while overcoming such highly reverberant acoustics.”
The DC280 provided significant cost savings because it is self-powered, which eliminated the need for external amplifiers and reduced the amount and expense of cable needed. In addition, a built-in Ambient Noise Sensing System further reduced the need for the microphones and cabling that would otherwise be required.
The successful outcome of the project has led Waddell to specify installing two more DC280s for the upcoming Stage 2 of the baggage hall extension project, to be completed September 2015. He will also be recommending them for all upcoming remodeling work. “On paper they’re a clever solution – but when you actually hear the speaker performing so brilliantly in this type of environment you really appreciate just how well-suited they are to this type of application.”