Specifications

Focusrite D2 and D3 Plug-Ins Guide22
With external side-chain processing, a plug-in's
detector is triggered by an external signal (such as
a separate reference track or audio source) known
as the key input.
A typical use for this feature is to use a kick drum
track to gate and tighten up a bass track, or a
rhythm guitar track to gate another instrument.
External Key
External Key toggles external side-chain process-
ing on or off. When this button is enabled, the
plug-in uses the amplitude of an external signal
(the key input) to trigger compression or limiting.
When this button is disabled, the plug-in uses the
amplitude of the input signal to trigger dynamics
processing.
Key Listen
Key Listen enables and disables auditioning of the
key input controlling the external side-chain. This
is useful for fine-tuning the compressor’s settings
to the key input.
Using a Key Input for External
Side-Chain Processing
To use a key input to trigger dynamics processing:
1 Click the Key Input selector and select the input
or bus carrying the audio from the reference
track or external audio source.
2 Click External Key to activate external side-
chain processing.
3 To listen to the key input that will be used to
control side-chain processing, click
Key Listen
to enable it.
4 Begin playback. The plug-in uses the input or
bus that you chose as an external key input to
trigger its effect.
5 Adjust the plug-in’s Threshold control to fine-
tune external key input triggering.
6 Adjust other controls to achieve the desired
effect.
External Key
Key Listen
Selecting a key input