What’s a Synthesizer & How Do They Work?

What's a Synthesizer

Ever since the synthesiser was created, they have taken the world by storm. They changed the face music forever, but also how we interact with musical instruments. With synthesisers came a whole new range of sonic possibilities that would blow the mind of not only the listeners, but the creators and musicians themselves. Never before have there been so many synthesisers on the market. There is an overwhelming choice of physical and digital synths in form of VST plugins. So, how do you even choose the right synthesiser when you don’t even know how they work? Well, in this article I’m going to answer all of your questions including: what is a synthesiser? How do they work? The different types, and their history. Let’s begin there then. How and when was the first synthesiser created?


The Birth of the Synthesiser

Moog Minimoog Synthesizer

The synthesizer wasn’t exactly created by one person alone. Rather, synths as we know them today came about through a series of developments. In the 19th century, pioneering scientists such as Elisha Gray started experimenting with electricity in order to control sound with a self-vibrating circuit. By using currents, they could create a vibration, amplify it, and create waveforms. Such experiments led to the invention of the Telharmonium, which was essentially a humongous 7-tonne early electronic organ. It worked by transmitting electronic signals over wires via motors. Telephone receivers were then used to amplify the sound via ‘horn’ speakers.

The RCA Mark II Synthesizer
The RCA Mark II

Throughout the early 20th century the development of electric instruments continued. However, it wasn’t until the 1950s where the instruments being made started to resemble synthesizers as we know them today. Most notably the RCA Mark II, which actually was -and still is- so big, that it takes up an entire room! Due to sheer size and appearance of the Mark II, it was dubbed Victor after the movie Frankenstein. Needless to say, this instrument was by no means easy to use.

It worked by automating oscillators and modules that were programmed by instructions printed on perforated paper. Yes, you read that right. These instructions would trigger certain modules that could control the intensity, timbre, and height of twelve inbuilt sinusoidal oscillators. Composer Milton Babbit used the RCA Mark II to compose his album ‘Composition for Synthesier’. If you haven’t heard it, well… let’s just say it’s an acquired taste. It is interesting though, to hear how the first synthesizer like instrument sounded.

The 1960s Changed the Synthesizer Forever

The 1960s were really the most evolutionary decade for what synthesizers have become today. Harold Bode began to make new instruments that instead of using vacuum tubes, used transistors. The benefit of using transistors meant you could increase or decrease the voltage, allowing greater control over audio and the components used within the instruments.

The innovations set out by Harold Bode influenced Robert Moog to create his own products. Robert Moog working experimental composer Herbert Deausch designed the first popular synth known as the Moog Modular Synthesizer, which used patch cables to layer different sound elements on top of each other. The added keyboard made it much more marketable, playable, practical, and user friendly. Without doubt Moog is the father of synthesizers and their popularisation. No, he did not invent the technology, but his innovative design gave birth to the era of the modern-day synthesizer.


How does a synthesizer work?

Vital Audio Synthesizer

Now to get to the nitty gritty. I’m not going to go into detail on the electronics of a synthesizer. To be honest even I get confused about that topic. I am though, going to cover the fundamentals of what synthesizers are actually doing and what you do when you use them to build soundscapes. The thing is with digital virtual synthesizers and plugins, it’s easy to get lazy. Why? Because they come with hundreds or even thousands of presets. It’s far too easy to just find a preset that you like the sound of, leave it as it, or tweak a few controls, and then hit record. I’ve been guilty of this too, must I confess!

But if you spend a bit time to fully understand the basics of building synth sounds, then you can walk proud with the knowledge you’ve acquired and can create sounds that no one else has. That’s the beauty of synthesizers. The tonal opportunities to create soundscapes are literally endless. Synthesizers are exceptionally versatile. You can create everything from gentle, beautiful, and lush sounding pads, to in-your-face, harsh, and aggressive sounding growls. So, what magic is going on here in order to achieve such a diverse range of sonic textures?


Waveforms – The Building Blocks of Any Synthesizer

Synthesizer Waveform Types

 It’s not as complicated as you may think. It all starts with an oscillator. Oscillators are simply that part of the synth that makes the sound. They are responsible for creating waveforms such as a sine wave. A sine wave is the most basic kind of sound that exists. It is a single frequency with no harmonics. So, they do not exist in the natural world. Any sound that you normally hear is comprised of many frequencies on top of each other. Sine waves are like the most basic building block for any synthesizer. They sound very clean and clear, similar to how they look.

It’s not as complicated as you may think. It all starts with an oscillator. Oscillators are simply that part of the synth that makes the sound. They are responsible for creating waveforms such as a sine wave. A sine wave is the most basic kind of sound that exists. It is a single frequency with no harmonics. So, they do not exist in the natural world. Any sound that you normally hear is comprised of many frequencies on top of each other. Sine waves are like the most basic building block for any synthesizer. They sound very clean and clear, similar to how they look.

Sine waves are like the most basic building block for any synthesizer. They sound very clean and clear, similar to how they look. Within synthesizers you can select different types of waveforms to be generated. For example, a saw wave which sounds more rough, jagged, and sharp. Square waves are sort of in-between the two and triangle waves, which sound quite similar to sine waves. The main principle behind any synth is to combine sounds together. The oscillators generate the sound waves, and using the synth we can layer them on top of each other. This is where interesting things start to happen. By combining sound waves, you can create a variety of tones and textures, but it’s the other elements of synthesizers add even more flavour and finesse.


Filters

Audio Equalzier Low Pass Fillter and High Pass Filter

Filters… well they filter things, duh! Within audio production you will be working filters frequently. Their whole purpose is to remove frequencies, whilst allowing others to pass. Thus, the name, High Pass Filters and Lower Pass Filters. HPFs allow high frequencies to pass through, whilst blocking out low frequencies. LPFs allow low frequencies to pass through, whilst blocking out high frequencies. Seems simple enough, right?

The benefit of using filters is give us more control sound. HP and LP filters are commonly used on EQs to remove unwanted sound. For example, maybe you recorded an acoustic guitar, but during the recording your microphone picked up a low rumble or truck passing by in the distance. Using an HPF, you could cut the low frequencies out. Likewise, you could use an LPF filter to cut out some harsh high frequencies. Filters in synthesizers do the exact same thing. You can use them to filter out the parts of the generated soundwaves that you don’t like. Giving you more flexibility in creating and setting the right mood for your sounds. You can also control the strength


LFOs

Low Frequency Oscillator

The next fundamental parameter that you can introduce into your synths are LFOs, which stands for Low Frequency Oscillators. What do oscillators do again? That’s right, generate sound. So, LFOs generate low frequency sounds that go up and down. These special types of oscillators play a pivotal role in shaping sound. You can assign LFOs to individual parts of other oscillators. For example, you could assign one LFO to the pitch of a sawtooth oscillator to make it rise and fall. Or you could assign an LFO to the volume of triangle oscillator, to make it fade in and out over time. You can adjust how the LFO sounds by changing its waveform type, the speed (rate), or the depth (amplitude). LFOs bring your snythesizers sounds to life by giving them movement.


Synthesizer Are Endless Fun

 

And those ladies and gentlemen, are the fundamental building blocks that make up any synth sound. What’s a synthesizer and ho do they work? Now you know. There are many synthesizers that get waaaay more complicated with assigning options galore. A good example would be Native Instruments’ Massive, which is a brilliantly powerful synthesizer. Slow down though before you even touch a synth like that.

Want my advice? The best way to get started is to open up a simple synthesizer in your DAW and just start with those building blocks. Add some oscillators together, play with some filters, assign an LFO -or two- to an oscillator, then finally add some effects. What kind of sounds can you create? Try to replicate or create something that you like or have heard in track that you love. Next, select some presets and look at what the settings are. Then play around with them, tweak the knobs, sliders, and parameters. Experimentation, exploration, and have fun is the best way to learn.

Once you’re familiar with the basics, then you can go on to build more diverse and complex sounds. Regardless, playing around with tremendously fun and additive. It’s easy to get lost for hours building sounds and selecting through hundreds of presets. I love them and will continue to use them throughout my musical journey.

I hope you enjoyed this article. Please feel free to ask me any questions in the comments section.

Chris

chrissoundlab.com

 

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