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Studio One: Vocoder

PreSonus Studio One Tips & Techniques By Robin Vincent
Published February 2023

Screen 1: The default Vocoder preset uses an internal Carrier signal at a frequency of 110Hz.Screen 1: The default Vocoder preset uses an internal Carrier signal at a frequency of 110Hz.

We don our shiniest Daft Punk helmets and get funky with Studio One’s Vocoder.

The Vocoder is an exciting new addition to Studio One’s list of native effects plug‑ins. It’s not your usual everyday plug‑in that earns its place in your channel strip; this is something a bit different, and you could even call it snazzy. We all know the vocoding effect when we hear it, but do we know how to make it work?

The Basics

A vocoder attempts to impress the harmonic ‘shape’ of one sound upon another. This works by extracting the dynamic profile of a number of frequency bands within one source, called the Modulator, and applying that profile to another source, called the Carrier. The Modulator, more often than not, is the human voice, and the Carrier tends to be a sustained synth sound or strings. A bank of filters splits the Modulator signal into however many frequency bands the vocoder has. Envelope followers track the level within each band, which is then applied to a corresponding filter bank through which the synth (Carrier) is played. So, the Carrier has its own frequency spectrum modulated by the bank representing that of the Modulator. The result is that you can hear the strings you were playing shaped by the voice that’s modulating the filters, to the point that the speech is (almost) intelligible. It’s surprisingly difficult to explain, yet you can hear it perfectly in your head, right?

To use the Vocoder plug‑in, you drag it onto the track that will be the Modulator. So, drag it onto a track of vocals, assuming we’re going for that classic vocoder sound. You don’t need pre‑recorded vocals, though, because you’re sitting there with the ability to generate them in real time. So, instead, try plugging in a microphone, add an empty audio track, drag in the Vocoder and hit the Monitor button.

When you speak into the microphone, you’ll be treated to a solid robot‑style vocoder voice with a fundamental frequency of 110Hz. This is the default Vocoder preset, and I think you’ll agree it’s already feeling pretty groovy. Open the Vocoder GUI (Screen 1) and grab the Frequency knob down at the bottom left. Speak the words “Intergalactic planetary, planetary intergalactic” into your mic while moving the knob and I guarantee you’ll be having a good time. One tip is to drop a compressor into the effects chain on the mic before the Vocoder. It helps give it a much more even and consistent response.

So, when does the synth get involved?

Classic Vocoding

So far, we’ve been using the internal Carrier, and we’ll do some more on that in a minute, but if we’re aiming for that classic sound, we’ll want to run some strings or a synth sound through it as the Carrier. To do that, drag an instance of Presence XT onto the next track and load up your desired sound; the ‘Solina Strings Viola & Cello’ preset is particularly good I think. We’re going to side‑chain it into the vocoder.

The Vocoder interface has a misleading Side‑chain button under Carrier Source. It’s misleading because it’s an LED, not a button. To enable the Carrier’s side‑chain, you have to visit the side‑chain part of the Studio One plug‑in interface above the GUI. Enable it and then select the Presence XT output as the source, as in Screen 2. Now play the notes E G A G F# B A B on your keyboard while saying, “We can boogie down, down upon”. Are we having fun yet?

Vocoders were often found integrated into string machines like the Roland VP‑330, and it’s in this rich harmonic content that we tend to find the sweet spot.

So, what are the best sound sources to use as Carriers? Vocoders were often found integrated into string machines like the Roland VP‑330, and it’s in this rich harmonic content that we tend to find the sweet spot. I’ve found that most of the string and electric piano presets of Presence work really well with the Vocoder plug‑in, as do the synth pads. Mai Tai is also a great source of synth sounds, although you may find you’ll have to turn it down a lot to prevent distortion. Some bolder and heavier sounds can overload the plug‑in, so softer, less aggressive sounds tend to work best. Also, the way the process works means that you tend to lose a certain amount of top end. Compensating by using a Carrier with plenty of higher frequencies will give a more even response.

Screen 2: To use a synth as the Carrier, select its output from the Vocoder plug‑in’s side‑chain menu.Screen 2: To use a synthesizer as the Carrier, select its output from the Vocoder plug‑in’s side‑chain menu.

Internal Carrier Source

The Vocoder comes with three internal sound sources:

  • Noise
  • Sawtooth waveform
  • Square wave

Noise is interesting because it appears to turn you into a 1970s whispering late‑night DJ crossed with the Borg and Gollum from Lord Of The Rings. But then noise finds it usefulness with Modulators other than the voice. For instance, it’s a great way of adding grit and air to drums, just by dialling the Mix knob back.

The sawtooth and square‑wave oscillators can be used for straightforwardly weird and robotic vocoder sounds. From conversations between Cylons, to the adorable GlaDOS from the Portal games, you will find the perfect sci‑fi voice in here. But another interesting factor in this section is found in the Follow knob. This parameter follows the envelope of the Modulator level and applies that to the pitch of the Carrier. It gives automatic movement to the otherwise static pitch of the synthesized voice and more often than not results in much hilarity.

Other Parameters

On the left we have the Modulator Envelope controls. They govern the ‘aggressiveness’ of the effect: how tightly it follows the contours of the input signal. On the right is a section called Unvoiced Replacement. This handles the problem that vocoders have in dealing with unvoiced, noise‑based sounds, like ‘f’, ‘t’, ‘s’ and so on. You can choose whether those sounds are replaced with noise, or allowed to pass through from the modulation source. The noise can sound a bit aggressive, and the direct sound does suggest that you should probably be singing in tune to the playing. You do have control over the level of the unvoiced replacement, though adjusting this often leaves me unsure if this enhances the intelligibility or ruins the vocoder effect. But with the right balance, it can improve the outcome.

Patch Matrix

Lastly, we have the patch matrix, which allows you to take the entire idea of vocoding apart and rewire it to your own ends. This is like the patchbay on the front of the Moog Vocoder and gives this plug‑in enormous sound‑shaping potential. On the other hand, if you just want that classic vocoder sound then this is the least interesting part of the plug‑in and best left well alone.

The matrix is configured so that you have your 20 analysers along the X axis at the bottom and the 20 band‑pass filters defined up the Y axis on the left. In the default setup, the connections between them form a diagonal line running from bottom left to top right. This indicates that the level from the lowest analyser is controlling that of the lowest filter, and so on. Making alternative assignments in the matrix changes this, and each patch point also has its own volume control, which you can access using the Volume button.

Going through the presets is helpful to understand the possibilities here. The 10‑Band preset halves the number of bands in use, giving it a more vintage feel. The Pitch Up and Pitch Down presets scale the vocoding up and down for pitch‑shifting effects. There are others that are either fun or ridiculous, but what should become apparent is that this is a source of experimentation.

What might not be obvious while you’re playing your synth and speaking into the microphone is that you don’t have to do all this in real time. The Vocoder plug‑in is part of your DAW, so you can drop it on an existing vocal track or clip. You don’t have to play the Carrier sound source yourself; you can have it sequenced, and you can MIDI‑automate the knobs. This frees you up to go beyond the clichés and find your own scenarios.

Alternative Serving Suggestions

Forget the ‘oohs’ and ‘aahs’ of synth or sampler choir presets. With Vocoder you can generate those choir pads using the actual vocal line. Copy your lead vocal to another track, add the vocoder and mix it behind and to the sides of the original as ethereal polyphonic chords. You could even move the vocodered track back in time a little to give an effected delay.

Using environmental sounds as Modulators can bring interesting textures to your pads and strings. Rhythms and drum loops can add gating effects and pull your synths into the movement of the track. In Screen 3, I’m running a drum loop as the Modulator and I can see that the snare is hitting on 570Hz. I am emphasising the effect of the snare on the synth part by increasing the number of bands linked to that frequency. It’s using the Vocoder as a manipulable source of filters rather than as a vocoding effect.

Screen 3: The patch matrix lets you adjust how Modulator and Carrier bands are linked.Screen 3: The patch matrix lets you adjust how Modulator and Carrier bands are linked.

Switching to the internal Carrier waveform and pushing up the Follow control can add some very nice pitch bends to percussion with some low blending. You also can put two synth sounds together and have the harmonic changes of one affect the other, giving a hybrid combined and morphable sound.

In researching this article, I found it remarkable how few ideas I came across that went beyond small variations on the classic themes. There’s something about the sound that captures our imagination and keeps us there with synthesized vocals, and a distant feeling that we really should go to a disco. Nothing wrong with a one‑trick pony if the trick’s a good one.