To prime your NLE Audio Channel do you apply your audio effects to an audio clip or an audio channel? The answer is, of course, it depends entirely on what you’re trying to achieve.
Special effects might be applied to certain scenes, certain clips – whereas more global tasks such as equalising, sweetening, enhancing and mastering ADR would require effects placed on an entire audio channel.
In a word, audio channels give you consistent and coherent processing in post to help unify audio collected from different sources.
It’s true to say that preparing channels to better receive audio clips, no matter the source or content, is a vital time saver and not only that, can be a quick fire way to ‘standardising’ a multitude of clips into one coherent sonic space – every sound is sat in one room, within the same four walls and not spread out over various psychoacoustic planes.
Set Up A Channel EQ Template
We use templates to save time but also to unify our workflow and create succession. The way we create is ‘our’ way, and over time we build strong methodology to that effect.
EQ, being your forever-friend in post, can be used to very subtly clean, contour, polish and embellish within audio channels, not just individual clips. For those new to the world of Equalisation there are a number of post production tools at hand that EQ and contour your audio for you.
|1||Insert an EQ on your audio channel, or set up your in built channel EQ|
|2||Cut all frequencies below 50Hz by using the ‘Hi pass’ band on you EQ. Depending on how your ears perceive the very low end of the audio source, bring the centre frequency up to 100Hz|
|3||The effect is an ‘unclogging’ creating a subtle openness especially in location recordings and environmental ambience.|
|4||The effect can be perceived as an ‘unclogging’, creating a subtle openness especially in location recordings and environmental ambience|
Warmth, Tone And Punch
Warmth is a generic word for the fullness and body in audio sources. It’s logical to say that subtle warmth achieved across each audio channel will result in a warmer final mix but it can also result in a more muddy, unintelligible mix.
With EQ, we often require a small ‘shelf‘ lift in the low frequencies that sit above the sub frequencies such as 80Hz to 180Hz.
This is where the ‘body’ of a rapturous roll of thunder lies, this is the thickness in the ‘thud’ of a suicidal corpse or of a felled tree.
|1||Engage a band in your EQ and set it to a ‘low shelf’. Between 80Hz and 180Hz. Your shelf should roll off, finishing around 200Hz|
|2||With channel EQ, subtlety is key. Set your shelf EQ from between +1.5dB and +3dB only|
|3||For extra punch, or ‘body’ you can add a ‘bell‘ boost in the low range from 60Hz to 100Hz|
|4||The ‘bell’ shape is a curve that centers around one particular requency and is much more accurate that the long flat ‘shelf’ type EQ|
|5||Anything from +1dB to +6dB can improve on thin, porous sounding audio, depending on the source material.|
|6||Be cautious when using strong, sharp ‘bell’ curves boosting frequencies on audio channels as they tend to sound very unnatural and over-processed.|
|7||As a rule, use broad, subtle lifting and cutting on audio channels.|
Compression And Control
Compression is available as a built-in audio channel effect in most NLEs for a reason.
The dynamic reduction of loud signals needs to be automated by compression, otherwise we would be lumbered with the arduous task of manually keying in level reduction as that tree fell, or thunder clapped across the shivering torpor.
It’s worth mentioning at this point that the effect of compression is a sensation more than a sound. For example, 10 channels each with with heavy compression settings will ‘feel’ very different (almost suffocated) to channels where no compression is used.
|1||Insert a compressor before the EQ plugin on your audio channel, or engage the in-built channel compression|
|2||One benefit of the compressor is called ‘makeup gain’. It adds character to audio by lifting levels back up after compression reduction|
|3||Set your ‘Attack‘ to slow – somewhere between 0.30 and 0.80 seconds.|
|4||Set your ‘release‘ to fast – somewhere between .5 and 50 milliseconds|
|5||Set the ‘makeup gain’ on your EQ plugin to +1.5dB|
|6||Set your threshold using your ears. During playback slowly lower the threshold control until you hear the dynamics (freedom, airyness, openness) of the audio compress and reduce.|
|7||Compressors reduce audio level dynamically during playback. Try to aim for no more than -3dB to -6dB reduction on average.|
|8||If you are compressing much more than this, then consider applying compression to individual clips on a case by case basis and not as a global channel effect.|
Stereo Sound Stage
When mixing a number of audio sources together – dialogue, street ambience, car horns, footsteps, weather sounds, dessert rain falling on corrugated cabins, the war cry of a rogue interstellar mercenary dropship, for example, it’s important to pay attention to the available sonic sound stage.
Setting predefined pan positions can help to separate sounds, and the frequency spectrum they are comprised of allowing you to see and locate each before you begin EQ and compression.
Will a cyclist moving at speed from left to right across a scene need panorama? With a stereo recording, no – that psychoacoustic movement is embedded inside the stereo information of the audio recording.
Mono sources will need more care, and also creativity.
|1||Set your pan control no more than 85 full left or 85 full right as extreme panning can sound very unnatural to the ear|
|2||For mono sound sources with no apparent visual location, such as a bird chirping, a plane passing overheard, a fracas in some distant part of the city, pan can be set up it’s position within the stereo field.|
|3||By making a copy of your mono audio channel, effectively doubling your audio source, you can create a ‘Pseudo Stereo‘ which can mimic stereo imaging|
|4||Pan channel 1 to the left 85|
|5||Pan channel 2 to the right 85|
|6||Set channel 1 to delay playback 20ms or more|
|7||Although Pseudo Stereo can sound quite cheap compared to natural stereo when used very subtly, way back in a mix, it can be a colourful psychoacoustic ‘bed’ for a richer, more immersive sound stage.|
|8||Sounds don’t often move the way objects do. Panorama is about binaural psychoacoustic location and so, during playback, use your ears to place sounds in natural spaces|
|9||Use your ears and your OWN audio analysis to select EQ frequencies to process|
|10||The last step is to use the output gain on the EQ plugin to give back audio level|
|11.||Set the EQ plugin output gain somewhere between +1.5dB and +3dB|
There’s a large emphasis placed on workflow in post and while setting up audio channel templates does address this, it should part of a larger, more personal methodology. Take away some or just one of these techniques and inter-lock them into your own daily practices to help streamline your NLE audio channel.
I hope this article helps you approach audio channels and audio clips differently, priming your project ready for audio post production… let us know how you get on!