10 Different Types of synthesis in Music Production

1. Subtractive Synthesis
   

It is one of the most common forms of synthesis. In simple words, you have a basic sound wave such as sine, square, tri and saw tooth wave being produced by the oscillator of the synthesiser and then you start subtracting harmonics from it using a filter and give the sound a basic shape using an ADSR envelope. It is like a sculptor chiseling away the material of a huge rock or some material to form a piece of art out of it. Similarly, subtractive synthesis helps in achieving a particular tone or sound by removing certain frequencies. (O’Sullivan, 2012)

It is basically considered as an analogue form of synthesis. However, it can be modelled to work digitally. Another name for it is east coast synthesis.

2. Additive synthesis

This is the opposite of subtractive synthesis. In this you have a basic sound wave like sine, square, triangle and sawtooth and then you start adding harmonic partials of a sine wave to it, creates a harmonically rich sound.

Examples of plugins that works on the principle of additive synthesis are Plaits from mutable instruments, razor from native instruments.

Additive synthesis features great precision and is a powerful way to reproduce any tone or sound using just sine waves.(O’Sullivan, 2012)

There is one more thing associated with additive synthesis called Resynthesis. In Resynthesis, a recorded sound is analysed and reproduced using sinusoidal harmonic partials. “Instead of starting with sine waves and attempting to describe a new waveform, resynthesis starts with the waveform and reproduces it.” (Douglas, 2019)

3. FM Synthesis

FM stands for frequency modulation and is a digital for of synthesis in which one sound wave is being modulated by another. FM synthesis starts with a pure sine wave ( carrier ) and is being modulated with another inaudible sine ( the modulator). As a result, harmonics are created in the carrier wave by the modulator wave and a combination of multiple carrier and modulators can create complex tones.

4. Sample Based Synthesis

It involves recording a sound into a digital memory. Back in the days, when electronic music just started this form of synthesis was quite expensive. The Akai’s rack mount S series and MPCs along with Ensoniq’s Mirage made it quite budget friendly for the producers back then to practice Sample based Synthesis.

“ Samplers can transform a continuous analog sound into the digital domain, allowing it to be processed and played back.” (Douglas, 2019)

Nowadays, technology has made it easy, precise and cheap for sampling literally anything digitally by using samplers that comes with a lot of DAWs like logic pro X, ableton live, FL Studio and many more.

There is an extension of Sample Based Synthesis called the ROMplers such as drum machines and synthesisers offer sound design capabilities but only with pre-loaded sampled sounds. For example, NI Kontakt, reFX Nexus, etc.

5. Wavetable Synthesis

It was developed by Wolfgang Palm. Wavetable synthesis is very common and used by a lots of electronic music producers around the world because of its flexibility and complex but unique evolving sounds. Wavetables are used by the oscillators of wavetable synths like Xfer Serum & NI Massive.

6. Vector Synthesis

“In contrast to wavetable synthesis, which interpolates between waveforms stacked side by side, vector synthesis gives the user control over the volume balance of four sampled waveforms arranged as if occupying four corners of a two-dimensional plane, with a joystick to crossfade between them.” (Douglas, 2019)

Although vector synthesis was something of an evolutionary dead-end, it does continue to pop-up in modern machines for example the Korg’s Kronos.

7. Spectral Synthesis

“Spectral synthesis is a kind of resynthesis that transforms a sound into a number of spectral bins, where each "bin" is a representation of its frequencies. The sound's noise content is also represented. This content is then displayed on a spectrogram, which represents the frequencies in terms of pitch as well as density. This allows for unique and targeted shaping of sound at the frequency level. It forms the basis for programs such as iZotope's RX as well as its Iris 2 sampler synthesizer.” (Douglas, 2019)

Iris 2 allows the user to the frequency bands that he wants to listen by drawing on the spectrogram ( visual representation of the frequency contents of the audio). This can be layered with similarly filtered samples and then run through traditional filters, envelopes and modulated.

8. Physical Modeling

This type of synthesis recreates the processes whereby a sound is made. It uses DSP to recreate the various properties that make up the sound for example the exciter ( bow on a stringed instrument/ breath for a woodwind), the resonant body of the instrument and the properties of the material from which the instrument is made i.e wood, metal, etc.

A few examples of plugins that uses physical modelling are Sculpture from logic pro X, the Korg Prophecy and the Yamaha VL1.

9. Granular Synthesis

It is a kind of sample synthesis but goes one step further and acts microscopically on the sample i.e breaking it down to smaller units called grains which can be manipulated by using grain size, volume, position to achieve some unheard sounds. Many sound designers use this form of synthesis to produce sounds for TV, games, movies and much more.

Some plugins that uses granular synthesis are Alchemy in Logic Pro X, Spectrasonics Omnisphere, etc.

10. West Coast Synthesis

When Bob Moog was developing his subtractive analog synthesis in New York, Don Buchla was creating the so called West Coast synthesis.

“Unlike East Coast subtractive synthesis, which starts with a complex waveform, Buchla's West Coast synthesis usually starts with a relatively simple waveform, like a triangle, and uses wave-shapers to add harmonics. Filtering is achieved with a low-pass gate, which acts like a filter and VCA in one.” (Douglas, 2019)

References

Douglas A.(2019).10 Types of synthesis explained: FM, Vector and more. [Blog Post]. Retrieved from https://reverb.com/news/10-types-of-synthesis

O’Sullivan S.(2012). The Basics of Sound Synthesis. [Blog Post]. Retrieved from https://theproaudiofiles.com/sound-synthesis-basics/

Studio D.(n.d.). Types of synthesis.[Blog Post]. Retrieved from https://www.dawsons.co.uk/blog/types-of-synthesis