Introduction to Synthesis (with Ableton's Drift Synthesizer)

Hi everyone! In today's lesson we are going to be learning about how to design your own sounds with a synthesizer! What we have done so far over the course of the semester, as far as selecting sounds, is to simply select a preset sound from the collection of factory presets shipped with your installation of Ableton Live. What we are going to learn today, is how to go one step further, and design your own sounds to use in your own music.

When we perform sound design with a synthesizer, what we are doing is essentially setting all the fancy knobs, buttons and sliders in a manner that makes the synth produce the specific timbre that we want it to produce. This applies to both those fancy hardware synthesizers that we see those synthesizer hipster YouTubers use (example of a synthesizer hipster YouTuber: https://www.youtube.com/@FallingIslands), as well as to software synthesizers, which is what you would find in your installation of Ableton Live.




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SUBTRACTIVE SYNTHESIS

Synthesizers come in many different shapes, sizes and architectures, but the most common synthesizer architecture is what is known as the subtractive synthesizer architecture. Subtractive synthesis works on the principle of starting with a harmonically rich and full sound, then cutting off parts of the sound in order to shape it to the desired timbre that you want. Hence the name, subtractive synthesis.


This is the most common synthesis type you will find, and many synthesizers, both hardware and software, operate on this very basic principle. We start with something full and rich, then we cut out the parts we don't want. It's like those ancient marble statues from Ancient Greece. They started life as shapeless blocks of marble, before being chipped at and hacked at painstakingly till the beautiful statue within emerged.


THE SYNTHESIZER YOU WILL BE USING

In Ableton Live, there are several subtractive synthesizer plugins built in. The one we will be working with is called Drift, as it is the one with the easiest-to-follow layout, and is a very good starting point for beginning to learn about subtractive synthesis. Other synthesizers which do make use of subtractive synthesis within Ableton Live include: Analog, Wavetable, and Operator (to name a few), but they fall outside of the purview of this lesson.


Open an instance of Drift by selecting the Instrument tab of the side menu, and dragging and dropping the Drift device onto your main Ableton Live workspace. Be sure to just grab the main device, and not one of its presets. We will not be using presets for this lesson.


You should see this loaded in the bottom of the interface:


PARTS OF A SYNTHESIZER
A synthesizer is comprised of various components that come together to form the sound generation apparatus as a whole. The main parts of a subtractive synthesizer are:

OSCILLATORS
FILTER
AMPLIFIER
LOW FREQUENCY OSCILLATORS (LFOs)
ENVELOPE GENERATORS

Most synthesizers that adhere to a subtractive architecture would have these five main components in some form. Below is a breakdown of what each of these components do.

OSCILLATOR

Oscillators are what generates the raw tone of a synthesizer. They can be set to several different simple waveforms, each with varying levels of harmonics or “brightness”. Common Waveforms include TRIANGLE, SAWTOOTH, SQUARE/PULSE, all of which feature in Drift.


FILTER

The filter is where the subtractive part of “subtractive synthesis” comes in. The filter shaves off frequencies from the raw waveforms specified in the OSCILLATOR section, and allows you to make a sound “darker” or “brighter”, or “thicker” and “thinner”. By default, Drift comes with a resonant LOW-PASS FILTER. As the name suggests, LOW-PASS filters let low frequencies pass through, while cutting off high frequencies. Drift also comes with a HIGH-PASS FILTER. HIGH-PASS filters allow high frequencies to pass.


The Freq knob, sometimes referred to as the Cutoff knob in other synthesizers, sets the frequency at which point frequencies start to be reduced or filtered by the filter. RES, or, Resonance, applies a boost to the signal at the cutoff frequency. Try boosting resonance to about 50%, then sweeping cutoff up and down. What effect does this have?


AMP

This is the final stage of the synthesizer which amplifies the signal before sending it out into the rest of your channel strip and signal chain. You can adjust the overall synth’s volume here. You can also increase the Sine Level, which adds a sine wave under all your sounds that enhances the bass content of your sound.


ENVELOPES

Envelopes in a synthesizer are essentially function generators that act as an invisible hand that move certain parameters for you. By default, Envelope 1 on Drift is hardwired to manipulate the amplitude or volume of the synth tone. Adjusting the ATTACK, DECAY, SUSTAIN, and RELEASE knobs manipulates the volume of the synthesizer in various ways. Below are details on what each value does.


  • ATTACK - The amount of time it takes for the VOLUME to go from 0 to its maximum value.

  • DECAY - The amount of time it takes for the VOLUME value to go from its maximum value down to the SUSTAIN level (which you set in the next stage).

  • SUSTAIN - The LEVEL at which you want the synthesizer to hold the VOLUME for as long as a note is held.

  • RELEASE - The amount of time it takes for the VOLUME to fall from the sustain level back to zero after the note is released.


By adjusting the four knobs on the Envelope, you can shape the contour of your sound. Furthermore, while the default routing of Drift's Envelope 1 is to the volume of the sound, the Envelopes on Drift can also be routed to other parameters like the FILTER CUTOFF FREQUENCY, the OSCILLATOR FREQUENCY etc. etc. What you route them to is up to you and how you want your sound to, well, sound like.

LFO

The LFO, or Low Frequency Oscillator, is another “invisible hand” that can be used to manipulate parameters in Drift, but unlike the Envelopes, it generates CONSTANT motion, rather than just one cycle of motion. You can adjust the RATE of the LFO, which determines the speed at which it oscillates and produces its modulation signal, as well as the shape of it.


The LFO can be used to modulate a number of parameters around the synth, including OSCILLATOR PITCH and FILTER CUTOFF FREQUENCY. Applying various amounts of LFO modulation to different parameters on the synthesizer can create cool effects such as vibrato, tremolo, and other weird wacky laser sounds.


CONCLUSIONS

While having all of this techno mumbo jumbo is certainly a useful starting point, there is no better way to get familiarized with the functions of a synthesizer than to USE a synthesizer. So I would highly encourage you all to dive deep into the various features that Drift has to offer. As always, if you have any questions, feel free to approach myself, Ben, or your seniors for assistance.


Happy synthing!









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