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Reason: Exploring BV‑X Multimode Vocoder

Reason Studios Reason Tips & Techniques By Simon Sherbourne
Published September 2022

This new Rack Extension could be all the vocoder you’ll ever need.

The latest premium Rack Extension from Reason Studios is the BV‑X Multimode Vocoder. So what, you may ask, does this bring to the Rack that we don’t get with the classic BV512 vocoder, which has been a standard feature in Reason for years? Well, lots...

Screen 1: BV‑X has a rich feature‑set but is simple to use compared to most vocoders: just plug and go.Screen 1: BV‑X has a rich feature‑set but is simple to use compared to most vocoders: just plug and go.There are two highlights that excited me about BV‑X. First, it makes vocoding easier by including a built‑in synth, so there’s no complicated setting up and routing or trying to remember the difference between a carrier and a modulator. (I will always have to look that up no matter how many times I learn it). Second, it has an ‘Auto Play’ mode, which pitch‑tracks the input signal so you have the option to apply vocoding without playing any notes. What I particularly liked about this is, when used with the Scale quantiser, you can get some uniquely flavoured variations of auto‑tune effects that could be massively useful in today’s pop, R&B and hip‑hop productions.

Vocoder Decode

Time for the obligatory vocoder recap... please skip ahead if you’re a vocoding champ. Simply put, a vocoder shapes one sound with another. More accurately, it analyses one signal, typically a voice, and applies its shifting spectral character to another signal, which is typically a synth tone. The result is that the synth sound seems to ‘speak’ or sing.

There’s huge room for variation within this basic formula. The results will depend on the tone and envelope of the ‘carrier’ (the sound that is being modulated) and the method and accuracy of tracking the harmonic character of the ‘modulator’ (voice). Vocoders often have ways to manipulate this sonic fingerprint to change the sound, and BV‑X has them in spades.

BV‑X Basics

Unlike the original Reason vocoder, BV‑X can simply be inserted onto a track or input channel, which for ease of explanation I’ll assume is a vocal. The veteran BV512 required two inputs to be connected up in the Rack: the vocal signal and another source to be modulated. (BV‑X can also operate like this, but in most cases you’ll probably use the simple self‑contained workflow).

With the default patch AutoVocode, you can simply hit play and, as if by magic, you’ll get a vocoded result. This is because this patch has Auto Play mode enabled. This detects the pitch of the source vocal, and plays the synth automatically, tracking the pitch.

Screen 2: If you’re using BV‑X in the Rack Extension plug‑in and want to play notes, you’ll need an extra MIDI track to route and record your keyboard.Screen 2: If you’re using BV‑X in the Rack Extension plug‑in and want to play notes, you’ll need an extra MIDI track to route and record your keyboard.If you want to play the synth yourself like a traditional vocoder, you need to get MIDI to the plug‑in. How that works will depend on whether you’re working in Reason standalone or in the Reason Rack plug‑in. In Reason, you can simply make BV‑X the MIDI target by clicking to the left of its name plate in the Rack. If you’re in a DAW, you’ll probably be running the Rack plug‑in in its Effect version inserted on an audio track. In most DAWs this means that you’ll need a MIDI track to target with your keyboard, and route the track’s output to the Rack plug‑in (see Screen 2).


OK, now we’ve got the basic mechanics working, we can start to experiment. Let’s start with the synth. This determines the primary tone and response of the vocoded output. On the left you can select Mono, Poly or Legato play modes. If you’re looking for that noodling lead‑line vocal effect à la 2Pac’s ‘California Love’ then go Mono, and you can reshape a vocal performance constrained to your played notes. For the classic vocoded wash, choose Poly mode and play block chords.

The main oscillator settings determine the harmonic character. You can pick from a selection of wavetable sources. Generally vocoding tends to be most effective with a bright and rich tone like the default sawtooth. Depending on the source material some pitch ranges work better than others as well, so experiment with the Octave control and the Harmonic Mix section to find the sweet spot that gives the best definition.

The Position parameter sweeps the oscillator through different shapes, and this can be modulated (along with most of the other parameters) via the familiar matrix common to so many Reason devices. Talking of modulation, the oscillator defaults to Gated mode, so is simply on or off. This often works best for the traditional vocoder sound as the source adds its own shape to the sound, but you can also switch to Envelope mode. There’s plenty of scope for experimentation here, such as triggering short envelope notes from a sequencer to create a stuttered, gated vocal.

Configuring The Modulator

The other main way to affect the sound is to mess with the vocoder section, which is the main green panel at the top of the device (Screen 3). Tabs at the top select between two modes: Vintage and Modern. These are two different methods for transferring the harmonic character of the input to the synth. Vintage is the classic mode, which BV512 also uses. It employs filters to track the level of the source across a set of frequency bands, and transfers this to a matched array of band‑pass filters on the synth. You can set the number of filter bands to get a more or less defined result.

Screen 3: A close‑up of the Vocoder section running in high‑resolution Modern mode.Screen 3: A close‑up of the Vocoder section running in high‑resolution Modern mode.

The Modern mode uses FFT analysis to get very precise snapshots of the harmonic content of the source, and apply this response curve to the synth. This can make the words and character of the original performance come through very clearly in the synthesised result.

Beyond these fundamental settings, there’s a whole heap of things you can do to alter the way the sound shaping is applied. The Modern mode, for example, has a Transfer Curve feature which distorts how the frequency response maps from voice to synth. Other options include formant shifting and a spectral spread which pans bands left and right. The Attack and Decay are particularly useful for dialling in different responses.

Everything that’s happening in the vocoder section is represented on the frequency plot display, and you can make manual adjustments by drawing a gain curve directly onto this.

Effects & Mix

The right‑hand strip of the BV‑X device is a mixer and effects section. The mixer is useful on this vocoder because a lot of the vocal processing effects you can achieve with Auto Play work nicely as a mix with the original signal.

Reason Studios were keen to use width as a key part of this effect, and alongside the spectral width control, the Unison and Reverb supply plenty of space. The middle multi‑mode effect is a bit more of an enigma. The Comb, Bit Crush and Distortion modes are fairly standard. Ring Mod, Bode Shifting and Buffering are a bit more out‑there. I’d say they are all really good for creating moments of interest in a track, but perhaps have limited use as overall effects.

The Scale option on BV‑X’s Auto Play opens a treasure chest of new variations of pitch quantising.

Pitch Tracking Effects

My favourite thing about the BV‑X is its scope for vocal processing beyond what you’d normally think of as vocoding. It certainly seems that the world isn’t even close to being over Auto‑Tune applied as a creative effect on a significant chunk of modern vocal performances. The Scale option on BV‑X’s Auto Play opens a treasure chest of new variations of pitch quantising.

Scale mode is pretty simple: once activated the Auto Play pitch tracking will steer towards the notes you select on the mini keyboard below. The Speed knob sets how fast this happens. You’ll get the best results if you know the key and just select the notes it uses, but if not you can just select all the keys and have it quantise chromatically. That can lead to unwanted stepping in glides or mis‑tunings though.

If you use the Hi Modern vocoder mode, and try out various oscillator wave options and settings you can get a vocoder output that is similar enough to the original sound that it sounds more like an interesting quantised gloss effect than traditional vocoding. It’s especially effective with the other effects and blended with the original. In fact the factory library is split between traditional vocoder‑style patches and vocal effects, so you can check out some possibilities.

The synth section also features a noise source, with variable colour. Dialled right up this turns vocals into a kind of whispered speech. Used subtly it can add intelligibility. It’s also great on rapped vocals. A patch I put together blends some noise with a lot of the oscillator sub‑harmonic to create a deep, slightly demonic voice that reminds of one of my favourite rappers Doseone.

There’s loads more to dig into than we’ve space for. I’d point to the modulation as an interesting area to explore. This has some intriguing and useful sources such as the detected pitch, tracking of pitched/unpitched vocal sections, and silence detection, which allow for some advanced shaping.  

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