The noise gate is capable of a variety of envelope shaping effects, and is a highly creative tool as well as a problem solver.
One classic trick is to put a more-or-less continuous signal through the gate, such as heavily distorted chords from an electric guitar, and then use the noise gate's external key to chop it up into a rhythm. Like this:
- Connect the guitar, through a distortion unit, to the gate in the normal way.
- Connect a drum machine, or other rhythmic source synchronized to the track, to the external key input.
- Switch the gate to external key.
- Set the threshold so that the gate triggers on a signal from the external key.
- Adjust the attack, hold and release controls to achieve the desired envelope.
You can't get the same sound in any other way and it is well worth trying out and adding to your repertory of techniques.
Drum envelope shaping
Another useful gate effect is to compress the sound of an individual drum, then gate it.
This works particularly well on drum samples which have a little bit of reverb on them.
A compressor can shape the envelope of the sound by emphasizing the attack (by setting a slow attack time on the compressor, allowing the initial transient to get through unaltered), or by allowing the reverb to increase in level as the drum dies away.
The noise gate can then further process the envelope using the attack, hold and release controls.
First popularized in the 1980s, gated reverb has become something of a cliche. But as a technique, it is still well worth knowing about. It goes like this:
- Connect the snare drum mic (say) to the mixing console in the normal way.
- Through an auxiliary send, send some of the signal to a reverb unit.
- Bring the output of the reverb back to a channel with an insert point. (If your console's auxiliary returns have insert points, then they will work fine).
- Connect the noise gate to the insert point send and return of the reverb channel.
- Connect the insert send of the snare channel to the gate's external key input. (You could alternatively derive this signal from another auxiliary send). Set the gate to external key (EXT).
- Set the hold and release controls so that the reverb extends beyond the end of the dry snare drum sound, but then dies away suddenly (long hold/short release).
You now have Phil Collins-style gated reverb! You could use a distant mic as the reverb source, as an alternative to the reverb unit.
If you're not using the external trigger input of your noise gate, you're missing out on so many interesting sounds that you can't get in any other way.