Specifications

Temperature and wind gradients

The effects of temperature and wind gradients are most noticeable when sound

systems are used outdoors, although not limited to this case. They exist when there are

differences between the temperatures or wind speeds of layers of air from the ground

upwards. The most common effect is to steer high frequencies away from the direction

that the loudspeakers are pointing. Typically if the ground is hot compared to the air

above or the wind is blowing from audience to stage, then sound will be steered

upward and conversely if the ground is colder or the wind is blowing from stage to

audience then sound will be steered downward.

Temperature and wind gradients are difficult to measure yet their effects can have

dramatic consequences for live sound projection. For this reason it is advisable to use

delay systems to suit the expected humidity conditions. See table at the end of this

section.

Wind effects

Side winds

Gusting side winds can dramatically effect mid and high frequency sound by

changing the propagation direction as follows:

Single sound source