Consideration of complex loudspeaker setups, including phase effects in the frame of environmental noise predictions on the basis of the ISO 9613-2 and the Nord2000

Abstract

One of the main goals of a perfect loudspeaker layout is to have equal sound distributions all over the spectator area. Modern setups achieve this by the positioning of the speaker arrays, time delays, the directivities due to the speaker chassis, but also due to coherency effects. Loudspeaker manufacturer like d&b audiotechnik GmbH do support their customers with planning tools such as ArrayCalc to predict the sound distribution in the spectator area, taking into account all of the above described effects. In the frame of approval procedures, for example for large open air events it is necessary to predict the sound levels in the surrounding for larger distances. Unfortunately the available tools are made for short distances and are not applicable since they are not considering ground or meteorological effects and reflections or screening is not treated. For this reason the implementation of the ISO 9613-2 [2] and the Nord2000 [3] in the noise mapping software SoundPLAN® was extended to consider such specific loudspeaker setups. During a validation process this implementation was cross checked for short distances against the well introduced planning software ArrayCalc. For long distances the validation process is still ongoing on the basis of real field measurements. Copyright © (2013) by Austrian Noise Abatement Association (OAL).