AGC Leveler
Definition: The AGC leveler (AGC stands for Automatic Gain Control) automatically lowers or raises the signal level for sounds of varying loudness in order to create a more consistent volume.
Application: The leveler can be used for podium and lectern microphones, where it is desirable to maintain a constant volume level when the talker may be moving back and forth from the microphone. The leveler detects a lower level coming from the talker when they are farther away, and compensates by gradually raising the gain. When the talker stops, the AGC gain will remain constant. If the talker then talks too close to the microphone, the AGC will gradually reduce the gain.
For the
AGC Select Button. Click on this button to select the leveler. Click a second time to bypass.
THRESHOLD. The threshold (Ê) determines the minimum input signal level for the leveler to activate. For input signals below the threshold, the gain is unity. For signals above the threshold, the gain is the minimum of the setting determined by the ratio or the maximum gain line (maximum gain, +12 dB). To prevent the possibility of gain increase in a
RATIO. The ratio line () pivots around the hinge, determining the amount the leveler adjusts the signal level toward the hinge.
ATTACK. The attack controls how fast signal levels moving away from the hinge are adjusted.
DECAY. The decay controls how fast signal levels moving towards the hinge are adjusted.
AGC HINGE. The hinge () sets the desired output speech level of the leveler. The hinge is a pivot point which determines whether a signal level is lowered or raised. Signal levels below the hinge (between the threshold and hinge) will be raised, while signal levels above the hinge will be lowered. To adjust the AGC Hinge, click and drag on the red ªHº box at the bottom of the graph, or click on the ↑ and ↓ buttons of the AGC HINGE edit box.
Maximum Gain Line. A +12 dB gain limit helps prevent excessive noise modulation or acoustic feedback problems for
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