There are several basic approaches to the synthesis of sounds in electronic music:
- Subtractive synthesis
- Additive synthesis
- Direct synthesis
Subtractive synthesis today is the most common form of synthesis, which is used by voltage-controlled synthesizers. In subtractive synthesis, we receive a signal (sound) that is rich in harmonics and filter it to create sound with the desired harmonic content. This is a classic sound construction model in which is a bunch: oscillator (VCO) – filter (VCF) – amplifier (VCA).
Additive synthesis is the mixing of a large number of sinusoidal waves of various frequencies and amplitudes to create sound with the desired harmonic content. Additive synthesis is also used in voltage-controlled synthesizers, but is less common because of its complexity associated with the addition of a large number of sinusoidal waves.
Direct synthesis is the generation of signals using data that is stored in the memory of a computer or a complex digital device. This form of synthesis is an order of magnitude more complicated and often requires knowledge of the “mathematics of sound” or complex computer programming, but in the modern world, synthesizers with this type of synthesis are not uncommon. Usually, their interface is very similar in structure to classic analog synthesizers, which makes it easier to understand synthesizers with direct sound synthesis. This type of synthesizers cannot be used with voltage-controlled systems, but there are also pluses: instruments with this type of synthesis are fully MIDI-based and well controlled via a digital interface.
In subsequent articles, we will take a closer look at each of the types of synthesis and try to get a complete understanding of each of the approaches.