The acoustic radiator consists of a “horn” type loudspeaker and hyperbolic sound baffle. Both the loudspeaker and the sound baffle are optimized in terms of spreading typical acoustic warning signals simulating the horn sounds of conventional motor-driven rotary sirens. The highest acoustic pressure is achieved in the frequency range of these signals, thus maximizing the siren’s coverage.
Usually two radiators are mounted on a steel pole. However, their arrangement is optional, which enables various radiation characteristics to be achieved, from almost circular, through elliptic up to directional characteristics.
The sound baffles are made of a special aluminium alloy, so that their durability is maximized and their weight minimized. They are virtually always installed outside on a high spot and are exposed directly to the effects of weather (sun, rain, snow, wind...) and very often to insects (wasps, bees...) as well. Experience from using plastic sound baffles shows that their life cycle in such severe siren usage conditions is very short and the cost of their maintenance and replacement highly exceeds that for aluminium baffles. Moreover, horn loudspeakers are designed to have the maximum resistance and output possible.
Telegrafia has developed several types of roof poles for installing sound baffles on different types of roofs and columns. These poles are designed in such a manner that their assembly, sound baffle included, is as easy as possible and at the same time all strength requirements related to their standard use are met. All pole types have been structurally evaluated and approved