Noise gate external key
Suppose you have taken every care over the setting of the threshold, but the gate still isn't opening and closing reliably on the snare drum.
The answer is to use an external key signal to open the gate. Here's the scenario:
- Feed the signal from the regular mic through the gate as normal.
- Tape a contact mic to the shell of the snare drum.
- Feed it via a preamp to the external key input of the gate.
- Switch the gate to external key ('EXT').
- Set the threshold etc. for reliable triggering.
Now, the gate is triggered by a signal that picks up virtually no external sound - only the sound of the drum.
What's more, the signal from the contact mic comes maybe half a millisecond earlier than the signal from the regular mic, which allows the gate to open a little in advance so that the transient of the drum is accurately captured.
It has to be said that this is probably an over-elaborate technique for most circumstances. But it works very reliably and is worth knowing about for the occasional difficult situation.