Following up my previous post on how to split a stereo track into two independent mono regions, this article is about Dual Mono, an almost mythological function in audio production which is always there, lurking in the shadows of your DAW, ready to be explored but too frightening to look at.
In fact Dual Mono is a really useful way of processing your stereo tracks.
When an Audio Workstation processes a Stereo track, every plugin and processor used will affect both its channels the same way, using the same parameters and settings.
Dual Mono basically splits the stereo signal into its two mono components, feeding them into the same processors/plugins but allowing the possibility of tweaking their parameters independently for each channel.
This is a very useful way to have more control over your stereo tracks, that is, if you want to process them with the same selection of plugins and the same order in the chain (if you don't, check out this article to learn how to split a stereo track into two completely independent mono regions).
Working with Dual Mono tracks can open new possibilities and deeper control over the sonic aesthetics of your production.
Below you can find how to fully take advantage of Dual Mono processing in Logic Pro X. In our example, we are compressing a stereo drums track and we want the compression to behave differently for the Left and Right channels, presenting them a slightly different content (in one channel the snare is more prominent and we don't want it to affect the other one when it peaks), meaning a smoother and more stable stereo image.
1 - Insert a plugin on a stereo track
On the Mixer window, or Inspector of your track, make sure you have selected a stereo track, checking the symbol on the input. Double adjacent circles mean stereo, single circle means mono. On the first audio FX slot, browse for a plugin, in our case Logic's compressor.
2 - Select 'Dual Mono'
When selecting your chosen plugin, choose the option Dual Mono.
3 - In the Plugin window, select either channel to setup
Logic has loaded the plugin on its Dual Mono configuration and now we can assign different parameters to each channel easily, opening the plugin window and, on the top side of it, selecting either the R or L channels.
After tweaking one channel you can select the other and you'll notice that the parameters will be set to their default position, meaning that they are independent from each other.
Little tip here: start adjusting it selecting the 'Couple' button, so that both the channels' parameters will be set the same way, then tweak them separately, deselecting 'Couple'. In this way you can start tweaking the independent channels from the same parameters' position that would work fairly well in Stereo.
Extra: You will have noticed also that there is a little gear button next to the 'L'. Pushing this button will open a configuration box that will let you change the plugin's channel processing from Stereo to Mid Side. If you select 'Mid/Side' then the 'L/R' buttons will show 'Mid/Side' instead, meaning that you will be selecting either the Mid or the Side channel for parameter's setup. More on Mid Side with the next article.
4 - That's it!
You have successfully used your first Dual Mono plugin!
The great thing about dual Mono in Logic Pro is that you can process your track this way on a plugin-by-plugin basis, meaning that you can have all of them working Dual Mono, Stereo, or a combination of both, selecting either Stereo or Dual Mono when choosing your plugin instance each time it is added to the audio FX chain.