Using Chorus Creatively on Vocals
Advanced tutorial on how to use modulation with different types of chorus effects to process vocals.
Chorus is not exclusive to processing vocals and guitars. It is one serious studio effect that needs as much consideration and respect as reverb. Each topology of chorus imparts a different colour onto the sound and it is this area we are going to explore. The power of any process is rooted in the processor’s modulation matrix. It is here where we structure and execute the behaviour of the processor. With regards to studio effects processors the modulation matrix determines how an effect influences the sound it is applied to, But before we jump into abusing the modulation matrix of a delay effect processor to achieve different chorus textures we need to understand what a modulator is.
What is a Modulator
A modulator is a device that controls the parameters of another device. The modulator is called the source and the device being modulated is called the destination. A good and simple example of a source modulator is the pitch wheel on a keyboard and in this instance the destination is pitch. In other words, the pitch wheel when moved alters the pitch of the sound being played. Almost anything can be a source modulator. Most synthesizer keyboards have a dedicated modwheel (modulation wheel) which can be assigned to a whole host of destination sources and we can replicate this scenario in our DAWs. In fact, we can design our own modulators and have them trigger all manner of processes. We can use Midi controllers to control any desired destination and now we can even use audio to modulate another piece of audio Now that we know what a modulator is let us take a close look at the chorus effect and how it is created.
With effects such as chorus, flanging, phasing and vibrato pitch modulation is used along with delay. With chorus, , an equal mix of the wet and dry signal is used with the wet signal being delayed and pitch modulated. The pitch is modulated using an LFO as the source and both the depth and rate are used to create varying ‘colours’ or textures of the effect.
The modulation depth is defined as intensity which is the range between the maximum and minimum values.
The rate determines the speed at which these maximum to minimum shifts occur. Too much depth when using chorus can sound as if the output is detuned whereas too little depth can make it sound less and less pronounced. Rate can have a dramatic effect on the chorus as slow rates create a more undulating and smoother effect whereas fast rates will create a speeded up wobble effect.
The relationship between rate and depth is very important and it is about finding a good balance between the two when processing sounds. The modulator shape is also critical as the shape denotes the periodic (unless chosen otherwise) cycling of the modulation destination. A sine wave shape will give a smoother cyclic effect, and is the most common LFO shape for chorus and flanging, as opposed to a square or pulse waveform which will have an extremely distinct effect as it cyclically switches between two delay times. Whereas flanging will take the output and feed it back into the input (feedback) chorus does not adopt this process creating a far more subtle shimmering effect.
Chorus is often used on guitars, basses (mainly acoustic) and keyboard sounds like electric pianos and so on. Although chorus can thicken and widen a sound it can also push it into the background, so you need to be wary of the rate and depth of modulation particularly when using it for these purposes as opposed to using it for a specific colour.
Stereo chorus is even more interesting and dynamic and works by inverting the polarity of the delayed signal and combining it with the dry signal in one channel whilst keeping the polarity the same for the delayed and dry signals in the other channel. The result is interesting in that one channel will have frequency peaks whereas the other channel will have frequency dips.
The modulation matrix is where all the clever routing and processing takes place. A wide variety of sources and destinations are offered along with detailed editing tools to help you to create any time based effects you choose. In this particular tutorial a delay effect processor is used to create different chorus textures and topologies.
We can simulate both digital and analogue chorus effects along with a whole host of other chorus type effects just by using the delay effect’s inbuilt modulation matrix.
In the video I explain how we can use a delay effect processor, and most notably Soundtoys Echoboy, to recreate the chorus effect. I explain in detail how to use the delay effect’s modulation matrix to shape new chorus textures. I use a vocal take in the examples and show you what settings to use to create the best chorus type effects.
Plugin used in this video: Soundtoys Echoboy
Topic covered in this video are:
- Chorus Topologies
- Modulating and modulation
- The Chorus Matrix
- Tape and Digital Chorus
- Advanced Echoboy techniques
- Understanding Wobble, Sync, Size and Diffusion
- Step Sequencing Chorus
- Envelopes, modulators and triggering
- Best Chorus EQ practices