Subtractive synthesis

Last updated

Subtractive synthesis is a method of sound synthesis in which partials of an audio signal (often one rich in harmonics) are attenuated by a filter to alter the timbre of the sound. While subtractive synthesis can be applied to any source audio signal, the sound most commonly associated with the technique is that of analog synthesizers of the 1960s and 1970s, in which the harmonics of simple waveforms such as sawtooth, pulse or square waves are attenuated with a voltage-controlled resonant low-pass filter. Many digital, virtual analog and software synthesizers use subtractive synthesis, sometimes in conjunction with other methods of sound synthesis. [1]

Contents

Examples of subtractive synthesis

The following is an example of subtractive synthesis as it might occur in an electronic instrument. It was created with a personal computer program designed to emulate an analogue subtractive synthesizer. This example will attempt to imitate the sound of a plucked string.

Whilst the following example illustrates how a desired sound might be achieved in practice, only the final three stages are really subtractive synthesis.

First, two oscillators produce relatively complex and harmonic-rich waveforms:

Pulse-width modulation is added for a dynamically changing tone:

The two sounds are mixed. In this case they are combined at equal volume, but any ratio could be used.

The combined wave is passed through a voltage-controlled amplifier connected to an attack, decay, sustain and release envelope. In other words, its volume is changed according to a pre-set pattern. This is an attempt to emulate the envelope of a plucked string:

Then pass the sound through a shallow low-pass filter:

In this case, to better emulate the sound of a plucked string, the filter cutoff frequency should start in the mid-range and to low. The effect is similar to an electric guitar's wah pedal.

In real music production, there is often an additional step. An oscillator with a very low frequency modulates one or more sounds over time, creating a dynamically changing sound.

See also

Related Research Articles

<span class="mw-page-title-main">Analog synthesizer</span> Synthesizer that uses analog circuits

An analog synthesizer is a synthesizer that uses analog circuits and analog signals to generate sound electronically.

Wavetable synthesis is a sound synthesis technique used to create quasi-periodic waveforms often used in the production of musical tones or notes.

<span class="mw-page-title-main">Modular synthesizer</span> Synthesizer composed of separate modules

Modular synthesizers are synthesizers composed of separate modules for different functions. The modules can be connected together by the user to create a patch. The outputs from the modules may include audio signals, analog control voltages, or digital signals for logic or timing conditions. Typical modules are voltage-controlled oscillators, voltage-controlled filters, voltage-controlled amplifiers and envelope generators.

<span class="mw-page-title-main">Voltage-controlled filter</span> Electronic filter circuit controlled with voltage

A voltage-controlled filter (VCF) is an electronic filter whose operating characteristics can be set by an input control voltage. Voltage-controlled filters are widely used in synthesizers.

<span class="mw-page-title-main">Korg OASYS</span> Workstation synthesizer

The Korg OASYS is a workstation synthesizer released in early 2005, 1 year after the successful Korg Triton Extreme. Unlike the Triton series, the OASYS uses a custom Linux operating system that was designed to be arbitrarily expandable via software updates, with its functionality limited only by the PC-like hardware.

<span class="mw-page-title-main">Korg MS-20</span> Patchable semi-modular monophonic analog synthesizer

The Korg MS-20 is a patchable semi-modular monophonic analog synthesizer which Korg released in 1978 and which was in production until 1983. It was part of Korg's MS series of instruments, which also included the single oscillator MS-10, the keyboardless MS-50 module, the SQ-10 sequencer, and the VC-10 Vocoder. Additional devices included the MS-01 Foot Controller, MS-02 Interface, MS-03 Signal Processor, and MS-04 Modulation Pedal.

<span class="mw-page-title-main">Korg Prophecy</span> Synthesizer released in 1995

The Korg Prophecy is a monophonic synthesizer released by Korg in 1995. one of the earliest commercial DSP physical/acoustic and analog "virtual" modeling sound synthesizers and Korg's first monophonic synthesizer since the Mono/Poly. The Prophecy employs Korg's Multi Oscillator Synthesis System (MOSS), which features digital oscillators capable of emulating synthesis techniques such as analog synthesis, FM and physical modelling. Emphasized for its portability, expressiveness, and engaging playability, a distinctive feature of the Prophecy is its multifunctional Wheel 3, nicknamed the 'log'.

<span class="mw-page-title-main">Korg MS2000</span> Synthesizer released in 2000

The Korg MS2000 is a virtual analog synthesizer produced by the Japanese electronic musical instrument manufacturer Korg.

<span class="mw-page-title-main">Korg DSS-1</span> Polyphonic synthesizer

The Korg DSS-1 is a polyphonic sampling synthesizer released by Korg in 1986. As Korg's initial entry into the sampling market, the DSS-1 combines sampling, additive synthesis, and waveform drawing with an analog signal path. The DSS-1 was released a time when major synthesizer manufacturers like Yamaha and Casio were beginning to explore sampling, an area of sound design dominated by companies like Fairlight, E-mu, and Ensoniq. Korg did not stay long in the sampling arena; the DSS-1 was the company's only sampler until 1998 when Korg introduced sampling options on their Triton and Trinity series of workstations.

<span class="mw-page-title-main">Synthesizer</span> Electronic musical instrument

A synthesizer is an electronic musical instrument that generates audio signals. Synthesizers typically create sounds by generating waveforms through methods including subtractive synthesis, additive synthesis and frequency modulation synthesis. These sounds may be altered by components such as filters, which cut or boost frequencies; envelopes, which control articulation, or how notes begin and end; and low-frequency oscillators, which modulate parameters such as pitch, volume, or filter characteristics affecting timbre. Synthesizers are typically played with keyboards or controlled by sequencers, software or other instruments and may be synchronized to other equipment via MIDI.

<span class="mw-page-title-main">Evolver (synthesizer)</span> Hybrid analog-digital synthesizer

The Evolver is an analog-digital hybrid synthesizer designed by Dave Smith and manufactured by Dave Smith Instruments. It was first released as a desktop version in 2002, then later a 37-key keyboard bearing the same synth engine as the Evolver desktop was also released. A polyphonic version of the Evolver, dubbed the Poly Evolver, was released in 2004 as a rackmount version, then a 61-key keyboard version of the Poly Evolver was released in 2005. The Evolvers were replaced by new high end models, the Prophet 12 and the Pro 2.

Casio's SDSynthesizers were a late-1980s line of analog synthesizers featuring a resonant filter. SD synthesis was traditional DCO-analog synthesis, with the main difference being that some of the SD waveforms' harmonic spectrums changed temporally, or dynamically in relation to the amplitude envelope.

<span class="mw-page-title-main">Oberheim Xpander</span> Analogue synthesizer

The Oberheim Xpander is an analog synthesizer launched by Oberheim in 1984 and discontinued in 1988. It is essentially a keyboardless, six-voice version of the Matrix-12. Utilizing Oberheim's Matrix Modulation technology, the Xpander combined analog audio generation with the flexibility of digital controls logic.

<span class="mw-page-title-main">Korg RADIAS</span> Synthesizer introduced in 2006

The Korg RADIAS is a virtual analog synthesizer and Vocoder, released by Korg in 2006. The RADIAS' MMT engine was based on the Korg OASYS synthesizer module, providing for several different synthesis methods, two of which may be combined in a single voice e.g. phase distortion synthesis can be combined with subtractive synthesis. The different synthesis methods employed by MMT represent the majority of methods used historically in other Korg synthesizers: digital waveguide synthesis Korg first used in the Korg Z1 and phase distortion synthesis was first used in the Korg DS-8. This flexibility allows for very realistic emulations of past Korg synthesizers, though stays away from trying to emulate the Korg M1 and the Korg Wavestation,. As well as using the in-built waveforms for the basis of sound creation, the RADIAS allows for the input of an external signal which may be routed through the various sound shaping devices. The RADIAS has a comprehensive matrix modulation specification and to further enhance a sound the 'Wave Shaper' module allows for various sound distortion effects.

<span class="mw-page-title-main">Korg Mono/Poly</span> Analog synthesizer, manufactured by Korg from 1981 to 1984

The Korg Mono/Poly (MP-4) is a paraphonic analog synthesizer released by Korg in 1981, bridging the gap between monophonic and polyphonic synthesis. Released in the same year as the Korg Polysix, as a complementary synth, The Mono/Poly is equipped with four VCOs and can operate as a four-voice paraphonic synth with limited capabilities, or as a monophonic synth using all four oscillators. Upon its release, it was the only monophonic synthesizer with an integrated quad-VCO design available on the market.

<span class="mw-page-title-main">Korg PS-3300</span> Polyphonic analogue synthesizer

The Korg PS-3300 is a polyphonic analog synthesizer, produced by Korg between 1977 and 1981.

<span class="mw-page-title-main">Harmor</span> Software synthesizer

Harmor is a software synthesizer created by Image-Line Software for the music production program FL Studio. It is available as a demo version within the software; however, it must be purchased separately in order to save projects that contain Harmor instances. Harmor is an upgraded and more elaborate version of its predecessor, Harmless. It was originally released with a 32-bit engine and upgraded to a 64-bit engine in 2013.

<span class="mw-page-title-main">Korg Minilogue</span> Polyphonic analogue synthesizer

The Korg Minilogue is a polyphonic analog synthesizer released in 2016 by Korg. It offers users four-voice polyphony with two analog VCOs per-voice and was designed to be affordable. It was designed by Korg engineer and synthesizer designer Tatsuya Takahashi, who said "the concept of the Minilogue was to build an analog synthesizer that doesn't rely on the fame and success of an old synth".

The history of home keyboards lies in mechanical musical instrument keyboards, electrified keyboards and 1960s and 1970s synthesizer technologies.

<span class="mw-page-title-main">Volca Modular</span> Analogue synthesizer

The Volca Modular is an analogue synthesizer manufactured by the Japanese music technology company Korg. It is part of their popular Volca series of affordable electronic synthesizers and drum machines. Like other Volcas, it sports a 16-step sequencer and can be powered by batteries.

References

  1. Collins, Karen. Game Sound: An Introduction to the History, Theory, and Practice of Video Game Music and Sound Design. MIT Press. p. 10. ISBN   9780262033787.