Have you ever found your final podcast material lacks the high fidelity finesse of others? A noise gate could be the solution for you! Noise gates have become a vital tool in all areas of recording, from bedroom podcasters to the best recording studios around. Here is a breakdown of how to incorporate a noise gate into your podcasting setup.
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What is a Noise Gate?
A noise gate may not be the most exciting of audio tools, but what they bring to the table can be paramount in a number of scenarios, including recording, mixing, and post-production. A gate responds to an incoming signal, allowing anything above the desired dynamic threshold to be heard. This can be perfect for getting rid of any computer fan noise, or other unwanted noises.
Gates are ‘all or nothing’. They’re either open or closed, as with physical gates! This is crucial to understanding the difference between a gate and a compressor. A gate will allow the intended signal through (open), without baring any effect on the result. The gate is only triggered (closed) when there is no signal above the set threshold.
Compressors, on the other hand, rely on a ratio, which dictates how much dynamic control the compressor performs once the threshold is passed. Noise gates are used best when they go unnoticed. As with manual audio editing, pops and clicks can devalue a recording of any kind, so it is worth knowing where attack and release come into play.
Why You Might use a Gate
A noise gate can be crucial in the removal of unwanted, low-level noise in a recording. This can be in either the acoustic environment itself, such as a hum of an electronic device or a laptop fan.
As recording locations may vary, a gate could even be put into use to control any unwanted subtle reverberate from the recording room. Careful control of the parameters can result in a controlled and intimate signal path, ideal for dialogue. A noise gate can also be useful in removing a level of white noise, introduced in the recording path. This could be due to either a microphone, cable, or pre-amp.
Therefore, a noise gate can give the impression of a perfectly clean signal path, allowing your content and material to be the sole focus for the listener.
Common Noise Gate Settings
As one noise gate plug-in may look entirely different from that of another company, fear not! The controls are completely universal, whilst being intuitive for the user.
Threshold refers to the sensitivity of the gate. A signal that is louder than this threshold will be heard, and the gate will cut out anything below the threshold. In most cases, the subtle sounds that are unwanted in a recording space, particularly when recording dialogue, are consistently quiet, meaning that the gate will not have to work much to remove it.
For example, a computer fan may be audible, but this can be easily tamed as the volume of the fan will largely be the same throughout.
This dictates the amount of dynamic attenuation that takes place. This can be tweaked to set a more subtle attenuation, removing any sudden silences which may seem unnatural.
Attack refers to the speed in which the gate opens (begins to let sound through). Generally speaking, with dialogue, it can often sound unnatural to have a fast attack, as the human ear is not used to such a swift transition from quiet to loud. This can result in an abrupt transient pop at the beginning of words.
Release time refers to how fast the gate closes (stops sound from passing through). Whilst a fast release time can result in some interesting and creative qualities, it is likely that it does not suit dialogue recording.
The ratio dictates how the gain reduction is applied when the signal is below the threshold. In most cases, a ratio of 100:1 will work, due to gates being fully open or fully closed.
Hold dictates how long the gate will remain open, even if the incoming signal has dropped below the threshold.
The side chain feature of a gate may not be useful in a podcast scenario, but could be worth knowing if ever the creative opportunity presents itself. So far, we have discussed how a gate is triggered, by the dynamic of its incoming signal. With the use of a side chain, a signal can be gated when a secondary signal triggers the noise gate.
A more useful usage of a side-chain is to incorporate a side-chain filter. This can be used to prevent low or high frequencies from triggering the gate. These filters are not applied to the overall signal, controlling only how the noise gate reacts.
These settings can depend on several variants; recording location, microphone and preamp choice, and of course, the material itself. A room can contribute a number of favorable, and unfavorable artifacts to a recording. In most podcast scenarios, a dry signal for dialogue is preferable so this is always a good start.
The settings may vary depending on how loud the incoming signal is. Below is a screenshot of Pro Tools’ Dyn3 noise gate plug-in, which shares a similar user interface as many noise gates.
As seen in the example above, the threshold has been set at -35.8dB, meaning that anything below, will be completely muted. Threshold is the one parameter that is most likely to vary dependent on the dynamics of the material. In this case, both the attack and release are set slightly slower than medium, which sounded natural. The graph of the Dyn3 can be a useful tool in understanding this.
Hardware v Software
As audio plug-ins continue to improve and become more accessible, there are many options which are greatly intuitive and sonically ideal. Where compressors are praised for adding their specific character and sonic footprint to a signal, gates differ, as they are truly transparent, almost acting as an automatic mute control.
Dependent on your recording software, there are endless possibilities for noise gates, both bundled with DAW’s along with third-party options, such as FabFilter’s Pro-G and Waves’ C1.
The biggest advantage of using a software-based noise gate is the option to have the gate applied in post-production. Not only does this allow for further tweaking at the editing/mixing stage, but prevents any destructive gating, which would otherwise by embedded into the recording if a hardware gate was used in the recording chain.
Another advantage of using a plug-in based noise gate is the option to recall settings instantly if ever problems occur. You can even save your preferred settings for specific recording scenarios.
Alternatively, noise gates can be found on some pieces of hardware, along with ‘all in one’ units such as SPL’s Channel One, which houses a preamp, compressor, and noise gate. As discussed, these processes would be applied on the record path, and will therefore be baked into the audio recording, committing these techniques in real-time.
Hardware also offers more tactile feedback between the unit and the user, which may be preferable. This essentially depends on the user’s working method.
How to Tell when a Noise Gate Could Help
If you’ve found yourself spending time cutting out any unwanted low-level sounds in your recordings in the editing stage, a noise gate could be the solution for you. A noise gate could instantly become part of your recording chain, with a “set it and forget it” approach. However, it is still preferable to record in a quiet location, with as little excess noise as possible!
How to Tweak the Settings for the Perfect Result and Identifying when the Setting are Incorrect
As with anything else, it is a good idea to experiment and find where it suits your productions. The settings that will vary the most are threshold, attack, and release.
If you find that the gate is being triggered too much, simply lower the threshold to taste. Monitoring a signal, either live or pre-recorded will direct you to your preferred settings. If using a plug-in, experimentation is risk-free, as the previous settings can always be restored.
If you feel that you can hear the gate working, it may be that the settings need some further attention. A gate tends to work best in the more subtle of situations, allowing the recording to still sound natural to the human ear. The idea is to create the notion that the recording has taken place in a noiseless environment, and should only be removing these unwanted artifacts, as opposed to having an audible impact on the dialogue itself.
The noise gate is the unsung hero of modern recordings, from podcasts to pop productions. These steps will hopefully elevate your recording techniques, taking you one step further to that perfect recording setup. Happy podcasting!