Oscillator Waveforms: Types and Uses – PART II

In part I we saw the most common types of waveforms an oscillator can have and now we are going to be giving some guidance on the type of waveforms to be chosen when creating a new synth instrument.

Creating instruments

Before going into the particularities of using some waveforms or others when creating a synth sound, we would like to remind you of a fact that we pointed at in part I: that when working on designing a particular synthesizer sound, it does not only depend on what type of waveform you start with. The waveforms give us some of the first texture of the sound. But the rest of sections of your synthesizer will be as decisive as the type of waveform when creating the main character of your instrument. We will show you in the following video:

Example: From a pad to a pluck synth.

We will show how using the same waveform and changing just some basic filter and ADSR settings we can go from having a pad to having a pluck synth. 

We are loading a simple preset in the Analog synth by Ableton Live: “accordion”. We turn the second Oscillator, the LFO and Vibrato off to simplify the exercise. 

Listen to how the pad we have made for this example is quickly turned into a stab sound by making it brighter with the filter section, and turning its AMP envelope settings very short. 

See that we have a square waveform, which, as we have mentioned in part I, is a bright and strong sound. It is not a waveform that would make you think of the base for a soft pad, at least from the theory perspective, but by turning down the cutoff and making the settings of the AMP envelope quite long, it is doing the job. And in fact, depending on the style of music you are composing, the square waveform may be giving your pad the perfect colour to fit into it.

Can you see now how subjective this issue can be?

Choosing waveforms

Having the previous exercise in mind, we may feel a bit more free to experiment and choose one or another waveform, or a mixture of them, as it usually happens. The key for being faster when creating a synth sound you have in mind, is to be familiar with how the basic waveforms sound like. That is something you can revise here, in our part I of Oscillators Waveforms: Types and Uses.

That way, by knowing the different intensities and qualities of the basic waveforms, you are able to construct any kind of sound, whether it is a lead synth, a bass or a background arpeggio.

You will then be calculating different amounts of each waveform, as if you were a cook, and then trying different adjustments to vary the depth of the sound. For example, by slightly detuning two or more oscillators, you can make a sound much fatter. 

Let’s have a look at the different kind of sounds you may want to build for your track and comment on their characteristics and waveforms they may be made of:

1 – LEADS

Lead sounds are normally melodic riffs that catch your attention and have you humming them long after the song has ended. They are on the front literally taking the lead as if they were the vocalist. And in the same way you would look for a vocalist with a big voice full of character, you will do the same when building your lead synths. 

Therefore, a lead synth can have any number of timbres and textures. It can be a full-open cutoff mono-synth-like square wave, or a triangle wave if you are searching for a less imposing sound. Or a sawtooth if you are looking for a full-fat sound. 

However, you may be looking for a “vocalist” with a more interesting personality, a more particular intimate storytelling voice maybe, or rather the opposite, a harsh intense voice that conveys a lot of power and tension. Then, you will probably take into account adding some percentage of sine wave to your lead sound for a more rounded feeling, especially for pluck or pierced leads, or rather, adding very irregular or noisy touches for getting a hasher sound. 

Here you have an example of an analog flute-style lead synth made of a mix of sine, square and sawtooth waveforms, which you can create with Ableton Live’s Operator (click here to go to the tutorial)

2 – BASS

There are many kinds of bass sounds depending on the style of music you are creating. From a very subtle bass sound that could be just made with a simple low sine waveform to a very acid bass just using either one square oscillator or a sawtooth oscillator (as in the famous Roland TB303)

In fact, the majority of bass synths with a bit of body will be made by a mix of sawtooth and square/pulse waves. A sine wave will be included in order to add the sub bass touch to the sound. 

Triangle waveforms are also quite used to create smoother and less synthetic bass sounds. 

Here you can find a tutorial to create a recreation of an MS20 Korg bass only with a simple square like waveform using Ableton Live’s wavetable synth (Read it here).

3 – PADS 

A pad sound has ambient or background qualities that will normally be creating space to your track. These can be lush filtered and evolving chords or atonal ambient soundscapes. Usually long attacks/release and sustained envelopes and the use of processing like reverb or delays will be the key for creating the mood and atmosphere qualities of a pad. 

Then, the decision on the oscillators chosen will not be decisive at all when creating a pad, but the way the sound is modified later on, as we saw in the video example at the beginning of this tutorial. 

Therefore, you can feel free to use any waveforms to create a pad, and find those that give the colour you like for your sound. You can use square and pulse waveforms for woodwind or string-like textures and soundscapes, sawtooth waveforms for more expansive and warm pads, triangle ones if you are looking for paler sounds, sine ones for making it more bassy, etc. 

Since long envelopes and low-filtering will always help you get the darker tone you may be looking for your pad, even the brighter and harsher combination of waveforms you have may be very adequate for a very interesting pad sound. 

Find a tutorial to create a lush house pad using sawtooth waveforms (Read it here).

And a tutorial to create a drone sound pad, in which you will realise how the reverb becomes key to transform any sound to have ambient qualities  (Read it here).

So if you want to further your knowledge on this topic and learn more, this guided masterclass is perfect to up your skills on synthesis and everything you need to know

Practice creating sound & have fun

We hope you may have a better understanding of the oscillator waveforms now, and how subjective it can be to choose one or another in order to create a particular sound. Now it is time for you to experiment with them and try and create different sounds of yours. You can create sounds from scratch or you can get presets and change just the waveform type in order to hear what a different colour your sound gets. The more you practice too, the faster you will be designing sounds. 

In order to be more in control of your waveforms, is to use synths that let you visualize the waves, or to have a wave visualizer such as the s(M)exoscope (download it here). This is especially useful with wavetable synths, since they have more complex oscillators in which the basic waves can be tweaked in all sorts of ways.