Using a Key Input for External Side-Chain ProcessingTo use a key input for external side-chain processing:1 Click the plug-in’s Key Input selector and select the input or bus carrying the audio you want to use to trigger the plug-in.
2 Click the External Key to activate external side-chain processing.3 Press the Spacebar to begin playback. The plug-in uses the input or bus that you chose as a key input to trigger its effect.4 During playback, do any of the following to fine-tune key input triggering:
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To hear the audio source you have selected to control the key input, enable Side-Chain Listen or Key Listen (depending on the plug-in). When finished, disable Side-Chain Listen/Key Listen to resume normal plug-in monitoring.
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To filter the key input so that only specific frequencies trigger the plug-in, use the filtering controls (if available) to select the frequency range.5 Adjust the plug-in’s Threshold control (if available) and other controls as needed.