THRESH (threshold) – This control sets the level where the noise gate will close. It should be set just above the noise floor of the system.
FLOOR – This sets how much the gate will attenuate the audio when it is closed. Keep this amount as small as possible to maintain noise specifications for the OEM customer.
HYSTERESIS – This controls how the gate will open after it is closed. For example:
When hysteresis is 0dB, the gate will close when audio level drops below the threshold. It will open when audio level rises above the threshold.
When hysteresis is 6dB, the gate will close when audio level drops below the threshold. It will open when the audio level rises 6dB above the threshold level.
This control is useful for keeping the gate closed until a full audio signal is present over the noise floor.
HOLD – This controls how long the gate stays open after audio drops below the threshold.
Values above 90 will cause a longer release.
Values below 90 will cause a short release.
RELEASE – This controls how the audio will fade to the floor level after the gate closes.
NOTE: Hold and Release values are not absolute millisecond values. They are interrelated in the Noise Gate algorithm for best possible sound quality. Higher values correlate to longer time for the gate to attenuate audio to floor level.
The Audio Engineer should listen to the effect of the Noise Gate in a quiet environment to verify the effect is right for the audio application.
Higher Hold and Release values are recommended to prevent the gate from opening and closing too rapidly when very quiet audio is present.
