Sound synthesis is the combining and manipulation of waveforms to create a new sound.

A synthesiser is the device that enables this to happen, offering all the functionality required to be able to alter the waveform in appealing and interesting ways.

Whether you are using a software synthesiser or hardware, the principle is that multiple components can be chained together in order to create and manipulate sound.

The basic components used in synthesis are:

VCO
Voltage Controlled Oscillator
This is the tone generator which creates the initial waveform. A synthesiser may have several of these which you can combine to create new waveforms using waveform interference.

Some synthesisers will enable you to choose between several options for the initial waveform such as sine wave, square wave and sawtooth wave, each of which have different sounds and harmonic content which can then be manipulated.

VCA
Voltage Controlled Amplifier
This controls the level of the signal.

VCF
Voltage Controlled Filter
The VCF is a filter with a controllable frequency. The filter may be a high pass, low pass or band pass filter. Adjusting the frequency of the filter will alter what frequency content of the signal can be heard.

LFO
Low Frequency Oscillator
A low frequency oscillator is so called because it is a control which oscillates at a much lower frequency than the ton generator (VCO).

The LFO is used to modulate characteristics of other components such as the amplifier level or VCF frequency.

ADSR Envelope – Attack, Decay, Sustain, Release
The envelope can be assigned to operate other components such as the amplifier or filter.

When assigned to the amplifier, the envelope controls the level of the signal in four phases:

• Attack
  – The initial impact of the sound when the sound is triggered.
• Decay
  – The recovery from the attack’s peak phase.
• Sustain
  – The level at which the signal remains.
• Release
  – The dissipation of sound once the trigger key has been released.

If your DAW has a synthesiser, experiment with the use of these components. If you feel lost at first, load one of the presets and change the settings to help you understand what they do.

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