How to Use Oscillators in Sound Design

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About 70% of pro sound creators believe that oscillators are super important for making unique and interesting sounds.

As you learn more about sound design, you’ll see that being good with oscillators is like a painter being good with their colours – it’s really important for turning your sound ideas into reality.

Each time you choose a waveform, you’re doing more than just starting a vibration. You’re setting up the complex mix of harmonics that will shape your sound’s character.

From the basic sine wave to the interesting and complex sawtooth, knowing how to choose and manipulate these waveforms is really important.

But how do these electronic pulses become the emotional tunes and textures that connect with listeners?

Oscillator Basics in Synthesis and Sound Design

At the heart of any synthesizer lies the oscillator, a fundamental component that generates the raw audio signals shaping the sounds you create. It’s your starting block in sound design, where the journey from simple beeps to rich, textured tones begins.

The process isn’t just about selecting a waveform; it’s about understanding how to mold and interact with these waves to serve your creative vision.

So how do they work exactly?

How Oscillators Generate Sound

Oscillators create sound waves through a process known as oscillation – literally movement back and forth.

Since sound is really just the vibration of air molecules, it can be generated by creating vibrations at specific frequencies (i.e. at specific intervals measured in hertz or vibrations/oscillations per second). Humans can generally hear vibrations between 20 Hz and 20,000 Hz.

In the context of audio and music, an oscillator is an electrical device or digital software program that generates a waveform using either electrical voltage (in analog devices) or math and algorithms (in software).

Voltage, often known as electric potential difference, is like the yardstick used to measure the amount of electric energy in each unit of electric charge within an electrical circuit. It is the force that pushes electric current through circuits, measured in volts (V) – either positive or negative.

Essentially, voltage is the ‘pressure’ that drives electric charges through a circuit.

Here’s a simplified explanation of how all this fits together:

  1. Voltage Variation: The basic principle behind an oscillator is the variation of voltage over time. This variation is what creates the waveform. Each of the basic waveforms above has a different pattern of voltage variation, which leads to different sounds.
  2. Frequency Control: The frequency of the waveform is typically controlled by a component called a voltage-controlled oscillator (VCO). The VCO changes the frequency of the waveform based on the input voltage. Higher voltage leads to higher frequency, and lower voltage leads to lower frequency. This in turn affects the pitch of the sound.
  3. Amplification: After the waveform is generated, it is usually amplified to a level that can drive a speaker or headphones. This is done by a voltage-controlled amplifier (VCA), which increases the power of the signal.
  4. Conversion to Sound: The amplified signal is then sent to a speaker or headphones, where it is converted into sound waves. This is done by vibrating a diaphragm in the speaker or headphones at the same frequency as the signal, which creates the vibrations in the air that we can hear.

Deeper Into Waveform Types and Uses

An oscillator can generate several basic types of sound waves:

  1. Sine wave: This is the most fundamental type of sound wave that represents a single frequency with no harmonics. Its wave pattern is smooth and pure. (Learn More)
  2. Square wave: This wave is characterized by its sudden leaps from high to low, providing a rich sound with a wide range of harmonics. (Learn More)
  3. Triangle wave: This wave form is similar to the square wave but has a smoother, triangular shape. It contains fewer harmonics than the square wave. (Learn More)
  4. Sawtooth wave: This wave form is named for its resemblance to the teeth of a saw. It contains a broader range of harmonics compared to the other wave types, giving it a bright, buzzy quality. (Learn More)
  5. Pulse wave: This is a variation of the square wave where the positive and negative phases are not equal, leading to a wide range of timbres. (Learn More)
  6. White Noise: This isn’t a wave form in the traditional sense, but oscillators can generate this. It contains all frequencies in equal amounts and is often used for percussive sounds and sound effects.
Waveform Shapes

Each of these basic waveforms has unique harmonic content and a characteristic sound. Understanding these waveforms is essential for harmonic exploration and crafting the textures in your sound designs.

Using Sine Waves

With the sine wave, the purest of all, you get a smooth, round sound that’s perfect when you’re aiming for subtlety. It’s the foundation for frequency modulation, allowing you to create complex tones by modulating one sine wave with another. The result can be as gentle or as radical as you desire, making it a versatile tool in your sound manipulation arsenal.

Sine waves are best used when creating the following types of sounds:

  1. Smooth and soft tones: Sine waves are perfect for creating smooth and soft tones because they represent the simplest and purest form of a wave with no harmonics.
  2. Sub bass: Sine waves are often used to create deep bass sounds in various genres of electronic music.
  3. Smooth melodic sounds: In electronic music, sine waves are used to create simple and clear melodic lines.
  4. Simulating natural sounds: By combining sine waves at different frequencies, it’s possible to simulate many natural sounds, such as wind or water.
  5. Bell and chime sounds: The clean sound of a sine wave is perfect for creating bell or chime-like sounds.

Using Triangle Waves

Triangle waves offer a slightly brighter tone due to its odd harmonics. It’s ideal for emulating woodwind-like textures and can be a great starting point for further sound shaping.

Triangle wave are best used when creating the following types of sounds:

  1. Flute and other wind instruments: The triangle wave is often used to simulate the sound of flutes and other wind instruments, as it creates a softer, more rounded sound than a square or sawtooth wave.
  2. Bass Sounds: Triangle waveforms can also be used to create deep and smooth bass sounds. They work well for bass because they have fewer harmonics, which makes the sound less harsh.
  3. Sub-bass tones: The triangle wave is ideal for sub-bass tones because it contains only odd harmonics, which are more pleasing to the ear in the lower register.
  4. Pad sounds: Pads are typically used for ambient or background parts, and the smoothness of the triangle wave makes it ideal for these types of sounds.
  5. Chiptune music: Triangle waves were commonly used in the sound chips of old gaming consoles, making them great for creating retro, chiptune style music.
  6. Bell-like sounds: With the right envelope and modulation, triangle waves can be used to create bell or metallic type sounds.

Using Square Waves

When you’re after a more assertive sound, the square wave comes into play, rich in harmonics, giving you that classic synth vibe that cuts through a mix.

Square waves are best used when creating the following types of sounds:

  1. Retro or chiptune music: Square waves are often used in older video game music and any modern music that wants to emulate that sound.
  2. Basslines: With the right modification, square waves can be used to create heavy and rich bass sounds.
  3. Percussive elements: With the right manipulation, square waves can mimic the sound of percussive elements like drums, claps, or cymbals.
  4. Harmonically rich sounds: Square waves contain a lot of harmonic content, which makes them useful for creating complex, rich sounds.
  5. Electronic organ sounds: Square waves can be used to approximate the sound of certain types of electronic organs.
  6. Synthesized vocal sounds: With the right manipulation, square waves can be used to create synthesized vocal sounds or “speak and spell” type effects.
  7. Distorted sounds: Because of their harmonic content, square waves can be used to create a variety of distorted sounds.

Using Pulse Waves

A close relative to the square wave is the pulse wave, which varies in harmonic content due to its adjustable width. This waveform blending capability opens up a realm of sonic possibilities, allowing you to dial in the precise character you’re after.

Pulse waves are best used when creating the following types of sounds:

  1. Chiptune or 8-bit sounds: Pulse waves are the basis for the classic 8-bit sounds found in retro video games.
  2. Bass sounds: Pulse waves can create a rich, full bass sound, especially when layered or modulated.
  3. Lead Synth sounds: The bright and harmonically rich nature of pulse waves makes them ideal for creating lead synth sounds.
  4. Percussive elements: With the right envelope settings, pulse waves can be used to create percussive elements like drum sounds.
  5. Sound effects: Many types of sound effects, especially those with a digital or electronic character, can be made using pulse waves.
  6. Arpeggiators: Pulse waves are often used to create arpeggiator sounds, due to their clear and distinct tone.
  7. Retro or vintage tones: Pulse waves can be used to create a retro or vintage aesthetic in a piece of music.

Using Sawtooth Waves

Sawtooth waves are different from simple sine waves and have a lot of harmonics, which means it can produce a wide range of sounds. This includes everything from strong basses to soft pads.

Sawtooth waves are best used when creating the following types of sounds:

  1. Brass Instruments: Sawtooth waves are often used to mimic the sound of brass instruments such as trumpets, trombones, and tubas due to their rich harmonic content.
  2. Strings: Violins, cellos, and other stringed instruments can also be synthesized using sawtooth waves due to their ability to produce a bright and sharp sound.
  3. Synth Leads: In electronic music, sawtooth waves are commonly used to create powerful lead sounds. The rich harmonic content of the sawtooth wave makes it perfect for cutting through a mix.
  4. Organ Sounds: The harmonic richness of the sawtooth wave also makes it ideal for creating organ-like sounds.
  5. Bass Sounds: Sawtooth waves are often used to synthesize bass sounds in electronic music due to their versatility and richness in harmonics.
  6. Pads: Sawtooth waves can be used to create lush, rich pads in electronic and cinematic music.

When you’re making music, the sawtooth wave can add a strong presence to your track. Whether you’re making a lead sound or a complex soundscape, this wave’s consistent structure gives you a good base to start from.

Waveform Selection

In order to really understand which waveform you should choose for a particular type of sound, it’s best to really experiment with each waveform and listen to the sound’s character as you manipulate the signal.

Try to compare what you’re hearing to real world (analog) instruments. Over time you’ll be able to take your idea from conception to completion through sound design techniques we discuss across this site.

But first, you should auditorily familiarize yourself with each of these waveform types.

Sound design is all about making unique sounds. One key way to do this is by picking the right waveform(s) for each instrument. The waveform you choose can really change how an instrument sounds. For instance, if you want a pure sound, you might use a sine wave. If you want a more full sound, you might go for a sawtooth wave.

By changing the shape of the sine, triangle, square, and sawtooth waves, you can change how an instrument sounds. For example, a sine wave, which is simple and clean, is great for soft sounds like flutes. On the other hand, a sawtooth wave, which is complex and rich, is great for bright sounds like a violin or a synth lead.

A square wave can give your sound a vintage feel, which is great for chiptune or old school synth basses. A triangle wave, which is a mix between a sine and sawtooth, is great for making your pads sound slightly textured but still gentle.

In sound design, the little details matter a lot. It’s not just about picking a waveform, but knowing how it can change the overall sound. As a musician, you’re also a sound designer, shaping waves into beautiful sounds. Remember, the waveform is your starting point; how you change it makes your sound unique.

Oscillator Techniques in Sound Design

Using multiple oscillators lets you create rich and varied sounds that a single waveform can’t.

When you layer oscillators, you can make more complex sounds. One way to do this is to mix different waveforms such as sine and sawtooth. This creates tones with a lot of harmonic content, like real instruments.

But it’s not just about layering waveforms. You can also use frequency modulation, where one oscillator changes the pitch of another. This method can create lively, changing sounds that seem to move and breathe. You’re not just adjusting sounds, you’re shaping them as they play.

There’s also filter modulation, where an oscillator changes a filter’s cutoff frequency, adding motion to your sound. It’s like using the filter to paint with sound, showing or hiding parts of the sound spectrum.

You can further shape these modulations with envelope shaping. This allows you to control the way your sound plays back. For example does the sound swell up to full volume, or does it hit/impact immediately?

You can mimic the natural sound of instruments or create something entirely new using these techniques of combining and manipulating oscillators.

An Oscilloscope Showing a Complex Wave Form

Advanced Oscillator Modulation

Let’s talk about making music more dynamic and exciting by using advanced sound wave techniques. One of these techniques is called frequency modulation (FM).

In FM, you use one sound wave to change the frequency of another. This can create new and exciting sounds that you can’t get from just using regular sound waves.

You can change the sound even more by adjusting the frequency and strength of the second sound wave. FM can be tricky to use, but it lets you create sounds that can be very natural or completely out of this world. The key to getting good at FM is to try different things, so don’t be scared to experiment.

But FM isn’t the only way to play with sound waves.

You can also change the shape of your sound waves while they’re playing. This is called pulse width modulation (PWM). With PWM, you can make a sound wave move and change, which can make your music sound more lively and exciting. PWM works really well when you combine it with other sound wave techniques.

Making new sounds isn’t just about adding more to the mix, it’s also about control and subtlety. Techniques like ring modulation or amplitude modulation let you add more complexity or rhythm to your music. Depending on how you use these techniques, you can make sounds that are like bells or sounds that are rough and gritty.

Using these advanced sound wave techniques can really open up your options for making music. By learning how to use these techniques, you’re not just turning dials and pressing buttons, you’re making your music truly your own.

What to Do Next

Thanks for reading this complete guide on oscillators for beginners. Next up, deep-dive into another area you’d like to learn about:

  • Understanding Harmonics and Overtones in Sound Design – Read Next
  • Using Filters in Your Sound Design – Read Next
  • Using Low Frequency Oscillators in Sound Design – Read Next
  • Utilizing Envelopes in Sound Design – Read Next
  • Utilizing Effects in Sound Design – Read Next