Before we get started, note that these tips are in no particular order and you can add them to your chain in any way you see fit.
Air Shelves are a great way to add some top end to your vocal, but it helps to know what frequencies are actually being boosted. With that in mind, let's use the Bertom curve analyzer and observe some various air shelves on analog emulated EQs.
This way you can recreate the curve with a parametric EQ. Here’s the Maag EQ’s air shelf, next an SSL shelf, and then an API emulation shelf.
Let’s listen to what these 3 can do to a vocal.
The harmonics of the vocal between 2 to 4kHz play a big role in adding to the clarity - if you know the most common note sung, you can find the exact frequency and boost it within that range. So if the most common note is A, A7 would be 3520Hz.
It helps to have an EQ with a piano roll, but if you know the frequency of the root note you can multiple find the right frequency. For example, I know A above middle C is 440Hz , so I can multiply by 2 to get 880, and again to get 1760, then again to find 3520Hz.
This is a simple but often overlooked tip - when adding reverb, some pre-delay will preserve the transient, otherwise, the reverb may make the initial consonant of the vocal unintelligible. A pre-delay of about 40ms will work well in most instances - but use a longer one if needed.
This trick also works for other instruments like guitar and synth so try it on those as well if they’re getting lost.
One issue with boosting the highs of a vocal is that it’ll boost unwanted highs like your sibilance - instead of fighting this with a de-esser, just isolate the sibilance and move it to a new track. Now you can be more aggressive with your processing without worrying.
Additionally, you can adjust the level of your sibilance or add some creative processing to better control sibilance’s role in your vocal’s clarity.
Exciters create high-frequency harmonics which can be really helpful when creating vocal clarity - some exciters let you control which analog processor you emulate, in turn giving you more control over which harmonics you create. Izotope’s exciter is a good example of this.
If we run a sine wave through it we can see how the different settings result in various harmonics. So in short, use an exciter to quickly add vocal clarity, but then consider which harmonic formation sounds best with your unique vocal.
Saturation, especially on higher frequencies, can add a lot of clarity to your vocal; however, it can exacerbate existing issues with the vocal. That said, I’m going to use soothe 2 on the vocal to dynamically attenuate resonant frequencies I don’t want to be amplified, then I’ll introduce my saturation.
This way I’m not fighting against other frequencies that may be masking clarifying aspects of the vocal. If you don’t have soothe 2, that’s totally fine - instead, use subtractive equalization to attenuate unwanted frequencies.
Another unique plugin that can add vocal clarity is TrackSpacer - if you place it on your vocal and use your instrumental or completing signal as the external side-chain, it’ll dynamically adjust the vocal accordingly. This way you can quickly delineate your vocal from the surrounding instrumentation.
Use very low settings with this plugin though since it’s a bit sensitive and can quickly become too aggressive.
This last tip is a great foundation for creative processing that’ll increaser the clarity of your vocal. In short, I’ll set up a bus and send my vocal to an auxiliary track - then I’ll use an EQ to attenuate my lows with a high-pass filter.
I’ll ensure that this EQ is in a linear phase mode to avoid phase cancellation between my original signal and this parallel one. Not that I have my vocal’s highs isolated I could increase the track’s level to increase clarity, or maybe add a bright reverb, or upward compression, etc.
Any additive processing you do to this parallel track will increase the clarity of your vocal, so get as creative and experimental as you want.