Configuring the ANS

Configuration Example

In this example, we will configure an ANS of the low range:

• Target Maximum SPL Broadcast is measured at 95dB.
• Minimum SPL Broadcast is measured at 65dB.
• Background ANL (Ambient Noise Level) is measured at 55dB.
• Signal to noise ratio required which is usually 10dB.

1. Calculate the Maximum ANS Threshold by subtracting the required signal-to-noise ratio (10 dB) from the maximum required SPL (90 dB):

• 95 dB − 10 dB = 85 dB

2. Configure the Maximum ANS Threshold by entering 85 dB as the Max Level in the SCT Noise Controls.

• This means that once the ambient noise reaches 85 dB, the system will output at maximum the predefined maximum SPL of 95 dB.

3. Configure the Minimum ANS Threshold by entering 55 dB as the Min Level in the SCT Noise Controls.

• This is the ambient noise level at which the ANS will begin adjusting the broadcast volume.

4. As the min ANS threshold is 55db you need to ensure that the ANS switch is set to the Lo and the corresponding setting in the Noise Control of the SCT matches.

• The Low LED on the front panel of the ANS should illuminate verifying the switch is in the correct position.

Up to twelve ANS sensors may be used to control a single zone or group of zones. However, ANS sensors which control the same zone must be connected to the same BMB01 Remote I/O Unit. Additionally one ANS sensor may control more than one zone, for instance if it is positioned at the junction of two zones. If multiple sensors are used in a single PA zone, then at any one time the system will raise the broadcast volume under the control of the sensor reporting the highest level of ambient noise.