Methods Of Sound Synthesis

Published: 04-04-2012

Back In the seventies when everyone had long hair and played guitars, synthesizers were a bit of a joke, played by German computer geeks, wizards and Rick Wakeman.

However, as the decade progressed and after the introduction of portable synths, they began to creep into popular music. By the mid 80s they were here to stay and inspiring a new breed of producers to create never before heard music.

Today we have access to thousands of software synth sounds at the click of a button but do we actually know the science behind them? Here’s a brief overview of the main methods of creating synth sounds.

Subtractive synthesis

The original form of sound synthesis. An oscillator generates a soundwave (sine, square, or saw for example) this is then modified using filters to remove or ‘subtract’ harmonics from the tone. Many of today’s virtual analog and software synths use subtractive synthesis, sometimes in conjunction with other methods of sound synthesis.

Soft Synth example: Native instruments Spark (available in NI Komplete 8)

FM synthesis (Frequency Modulation)

Developed in the early 80s FM was the first commercially successful and affordable synthesis type. Rather than subtract from a big fat waveform as in subtractive synthesis, FM started by using several Sine Waves at user selectable frequencies and then altered them in various ways to come up with tones. This resulted in an entire universe of new sounds which is still massively popular with Dubstep producers, who utilise FM to get ‘that’ bass sound.

Soft Synth example: Native instruments FM8 (available in NI Komplete 8)

Additive synthesis

Additive synthesis emulates the way in which sound is created in nature. An additive synthesiser has multiple oscillators producing a collection of sine waves all played at different frequencies. By combining these sine waves together a complex and more natural sounding waveform is created.

Soft Synth example: Native Instruments Razor (available in NI Komplete 8)

Wavetable synthesis

This form of synthesis is ideal for slow pad-like and unusual harmonic sounds. The essential concept involves morphing between a number of different waveforms or ‘tables’ created by additive synthesis resulting in complex evolving sounds and rhythms.

PD/PM Synthesis:

Phase Distortion (PD) or Phase modulation (PM) as it is otherwise known is a bit of a forgotten gem. Casio were the unlikely pioneers to start the trend in the late 80s and after a brief flirtation they gave up and went back to making the toy keyboards we all use to own as kids. It uses an algorithm to create a sine wave, and then uses a second algorithm to distort the “shape” of the sine wave to create a totally new waveform.

Soft Synth example: CubicAudio Proton

Granular Synthesis:

Based on the same principle as sampling, Granular Synthesis is a method by which samples are broken into tiny grains which are then played back at different speeds, phases, volumes and pitches to create all kinds of intriguing timbres. It works great when played back at low speeds for ambient soundscapes and effects.

Soft Synth example: Native instruments Kontakt (available in NI Komplete 8)

All software featured is available at soundsonic.com

Categories: Tech Talk, The Science of Beatmaking