Significant attenuation to high frequency of a sound system occurs when that system is used over
extreme distances, we call this effect ‘air loss’ To combat this, and provide the best possible HF
response for a given condition, EAW employs an automatic air loss compensation algorithm in its
Adaptive Products.
Air loss increases with distance, as distance increases, so will air loss.
Air loss pre-emphasis filters
To a limited extent, the high frequency response of a loudspeaker can be boosted to counteract the air loss we’ve observed in the previous examples. Air loss is a natural phenomenon and is a natural part of the listening environment, there is benefit to adding in high frequency content that is lost due to distance, but it must to be balanced so as to not have a large negative impact on the headroom of the high frequency transducers, and should be kept at a reasonable level so as not to negatively impact the tonal balance of the system. To achieve this, we employ a combination of filters to compensate for the effects of air loss, these include a low pass filter and a boost matched to the air loss curves at a given distance. The Low-pass filter is an important aspect of our approach to air-loss compensation and ensures that the compression driver producing the high frequency content is operating as efficiently as possible.
Air loss and Humidity
While air loss is the most significant contributor to high frequency attenuation over distance,
temperate and humidity also play a significant role. You’ll notice that in general, as humidity increases, air loss will decrease. This is due to the increase in moisture in the air which serves as a medium for sound to propagate Resolution will automatically compensate for the user entered humidity percentage, using that as a variable in the air loss compensation algorithm, applying additional air loss compensation to battle low levels of humidity. as temperature increases, air loss decreases. As with humidity, Resolution will automatically compensate for the user entered temperature and adjust the air loss pre-emphasis filter accordingly to compensate for varying temperatures.