The event took place in the Camama Stadium 11 de Novembro in front of an audience of 100.000 and featured several major Angolan artists and the President of Angola himself, José Eduardo dos Santos who delivered the main speech.
Clearly, presidents like to be heard and, being no exception, José Eduardo dos Santos' words were distributed to an audience covering some 110.000sq.m by a large Adamson Y-Axis system powered by LAB gruppen amplifiers. Three delay towers, each situated some 500m from the main PA and equipped with tri-Wi Rx units, were fed their respective audio signals wirelessly from a central tri-Wi Tx unit from the main stage.
The entire event was planed and supervised by Wladimiro Garrido, technical director of the Portuguese pro audio distributor Merging Select, based in Lisbon.
Said Wladimiro, "Running cable in trenches across a stadium that would be occupied by 100,000 people was quickly ruled out as being both impractical and costly, so we explored the idea of sending the signal wirelessly. We initially considered an IEM system as the way to go but were concerned that the distance would represent a challenge. Additionally, while IEMs are great at doing the job they were designed for, they lack the frequency range that a full spectrum PA can deliver.
"Having stumbled across tri-Wi we discovered that it offered just what we needed: full spectrum audio, low latency and an amazing wireless range."
A tri-Wi system comprises of two main components, the tri-Wi transmitter [Tx] and the tri-Wi receiver [Rx] used in combination with a variety of antennae to transmit audio signal up to 2.3km. An optional Repeater unit [Rp] is available where greater distances are required.
(Jim Evans)
