Editing Subtractive synthesis (section)

==Method==
The following is an example of subtractive synthesis as it might occur in an electronic instrument to emulate the sound of a [[Pizzicato|plucked string]]. It was created with a [[personal computer]] program designed to emulate an analogue subtractive synthesizer.

===Source Sound===
First, an [[electronic oscillator]] produces a relatively complex [[waveform]] with audible [[overtone|overtones]]. Only one oscillator is necessary, and the number can vary widely. In this case, two oscillators are used:
{|
|- 
| {{Listen | filename = subsynth-wave1.ogg | title = Waveform #1 | format = [[Ogg]] | pos = right | help = yes }}
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[[File:Waveform 1.jpg|alt=Closeup view of waveform in the audio sample.|thumb|Closeup [[oscilloscope]] of Waveform #1.]]
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| {{Listen | filename = subsynth-wave2.ogg | title = Waveform #2 | format = [[Ogg]] | pos = right | help = no }}
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[[File:Closeup oscilloscope of Waveform 2.jpg|alt=Closeup oscilloscope of Waveform #2.|thumb|Closeup oscilloscope of Waveform #2.]]
|}
[[Pulse-width modulation]] is applied to both waveforms to create a more complex tone with [[vibrato]]:
{|
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| {{Listen | filename = subsynth-wave1pwm.ogg | title = PWM waveform #1 | format = [[Ogg]] | pos = right | help = no }}
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[[File:Closeup of pulse-width modulated Waveform 1.jpg|alt=Closeup of pulse-width modulated Waveform 1.|thumb|Closeup of pulse-width modulated Waveform 1.]]
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| {{Listen | filename = subsynth-wave2pwm.ogg | title = PWM waveform #2 | format = [[Ogg]] | pos = right | help = no }}
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[[File:Closeup of pulse-width modulated Waveform 2.jpg|alt=Closeup of pulse-width modulated Waveform 2.|thumb|Closeup of pulse-width modulated Waveform 2.]]
|}

The pulse-width modulated sounds are now combined at equal volume. Combining them at different volumes would create different timbres. The result is a 2-second '''source sound''', which is ready for subtractive synthesis.
{| 
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| {{Listen | filename = subsynth-wavemix.ogg | title = Combined waveforms | format = [[Ogg]]}} 
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[[File:Combined waveforms and pulse-width modulation.jpg|alt=Combined waveforms and pulse-width modulation.|thumb|Combined waveforms and pulse-width modulation.]]
|}

===Subtractive Synthesis===
The combined wave is passed through a [[voltage-controlled amplifier]] connected to an [[Envelope_(music)#ADSR|envelope generator]]. The parameters of the sound's envelope (attack, decay, sustain and release) are manipulated to change its sound. In this case, the decay is vastly increased, sustain is reduced, and the release shortened. The resulting sound is audible for half as long as the source sound:
{|
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| {{Listen | filename = subsynth-mixenv.ogg | title = Enveloped sound | format = [[Ogg]] | pos = right | help = no }}
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[[File:Enveloped waveform.jpg|alt=Enveloped waveform.|thumb|Enveloped waveform.]]
|}

With its new envelope, the sound is run through a [[low-pass filter]], which reduces the volume of higher overtones:
{|
|- 
| {{Listen | filename = subsynth-nomodfilter.ogg | title = Low-passed sound | format = [[Ogg]] | pos = right | help = no }}
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[[File:Low-pass filtered waveform.jpg|alt=Low-pass filtered waveform.|thumb|Closeup of low-pass filtered waveform.]]
|}

To better emulate the sound of a plucked string, the filter's [[cutoff frequency]] is lowered.
{|
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| {{Listen | filename = subsynth-modfilter.ogg | title = Final sound | format = [[Ogg]] | pos = right | help = no }}
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[[File:Final waveform.jpg|alt=Final waveform|thumb|Closeup of final waveform]]
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| {{Listen | filename = subsynth-arpeggios.ogg | title = Some arpeggios | format = [[Ogg]] | pos = right | help = no }}
|}