What Is A Noise Gate & How Do You Use It?
What’s Up Producer!
Today’s Blog is all about Noise Gates. They are really versatile tools. You can use them to clean up ‘spill’ or ‘bleed’ from one mic into another, for example the high hat spill in the snare mike. You can use them to clean up the in between bits of a vocal (reduce breathe noises, background or room noise, and so on); or clean up the guitar part; yeah, you know, when you record a perfect guitar part, and the hum of the amp bleeds through in the quiet parts!
There are also more creative uses for the noise gate, and in the video, Bronwen from www.rapponline.net demonstrates the noise gate’s technical as well as more creative uses, showing how to use a ‘ghost’ track to trigger the noise gate to create some rhythmic effects. Noise gates usually have five main parameters: threshold, ratio (reduction), attack, hold and release. Some also offer a few extra options, have a good read through the blog to find out about these parameters and what they do!
Threshold – this sets the level at which the gate opens to let the sound through. The higher the threshold, the louder the sound (stronger the signal) must be to open the gate. The lower the threshold, the more sound that will pass through when the gate is open.
Ratio – the balance between the original sound and the gated sound. Attack –The attack time controls the speed of the gate opening. The time is in microseconds, under one second. A little trick and technique here: a gate that opens too quickly on a slower signal, the fast attack can produce a click sound. So, If you are working with percussive instruments , then you should think about using nice fast attack times and then use slower attack times (10 ms or more) for pretty much everything else. If you are getting clicks in your sound when using the noise gate, then try increasing the attack time.
Hold – the minimum time that the gate stays open. When there is a high speed fluctuating signal level, the gate will constantly open and close. This is called ‘chatter’. Most Noise gates are often internally set to a minimum of 20-30ms to prevent chatter, although it is sometimes possible to set your own time. Some Noise Gates offer another type of chatter-control called Hysteresis. What happens here is that the threshold automatically increases a few dBs for subsequent gate openings and then decreases a few dBs for closing the gate. The whole idea behind this, is that any sound of really fast and varied levels won’t produce too much ‘chattering’.
Release - Also measured in microseconds, the release time determines how long it takes for the gate to go from fully open to fully closed. The way to determine the release time is to consider how you want to use the Noise Gate. Noise elimination? Or effect? A quick technique to help you is that a fast release quickly cuts off the sound whereas slower release is more like a fade out.
Not typically found on all noise gates, but a really useful parameter if it is there, is the Range. Simply, the Range turns a signal down that is under the threshold instead of muting it completely. This means with the gate closed, some of the sound can be still be heard, although it is much quieter.
The R-Loops Team.