Atmosphere
User Manual
AtlasIED.com
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Ambient Noise Sensor Placement
Correct placement of the X-ANS Ambient Noise Sensor is a critical, aspect of a good system installation. The X-ANS provides real-time noise level
measurements to the Atmosphere’s system that, in turn, allows the system to continuously adjust the zone output level to maintain an intelligible
announcement above the current noise level in the zone. No system calibration is required, because the Ambient Noise Compensation system uses
advanced adaptive filters to differentiate between system audio and ambient noise.
The sensors must be placed in a location within each zone to allow for optimal detection of the ambient noise level while maintaining the ability to
distinguish between the noise and the PA system. This location is dependent on the speaker placement and the acoustical characteristics of the space
where the sensor is located. Due to this complexity, there is no single rule to define exact sensor placement. However, there are five basic rules that
should always be considered when placing the X-ANS Ambient Noise Sensor.
RULE 1: The distance between the sensor and the audience should be less than the distance between the sensor and the loudspeaker.
In most installations, the sensor will be placed in the ceiling located in the zone that it will control. The ANC system uses an adaptive filter to “learn”
what the audio system contributes to the overall zone ambient noise level and then filter that portion out of the calculation when adjusting the level.
When sensors are placed too close to the loudspeaker, the direct sound from the loudspeaker effectively masks the ambient noise from the sensor.
While the algorithm should prevent the system from turning the level up based on the speaker output, the level will not properly track in real time as
levels change since the sensor cannot properly detect the current level of ambient noise. Placing the sensor in a location that allows it to be closer to
the source of the noise than the adjacent speakers will prevent the masking effect from impairing the performance of the system.
