This is a very complex synthetic form, and thus the opposite of subtractive synthesis. In order to generate any sounds, in the additive synthesis no overtones are filtered, but rather various sine base sounds are added. Each of these numerous partials is, in principle, an oscillator with time-variable volume control available. Although this calculation is computationally intensive, conversely it allows a precise construction of sounds. The disadvantage: Instead of moving a filter regulator, several parameters must always be changed.
This type of synthesis is simply structured and the most widely used. One finds the subtractive synthesis or its derivatives in 90 percent of all synthesizer models. The principle: The sound of overtone-rich waveforms
The subtractive synthesis is easily structured and widely used.
One or more oscillators are formed by a filter that subtracts overtones. Envelopes, LFOs and other elements provide a dynamic volume, but also the timbre. In general, the construction of the subtractive synthesis provides at least three blocks:
1. The pitch control by MIDI notes
2. The sound shaping through the filter unit
3. The volume shaping by an amplifier.
The oscillator thus defines the pitch and the basic sound, the filter unit the specific sound and the time-dependent sound change, the amplifier the volume control. The course of a signal through these levels decisively determines the produced sound.
The wavetable synthesis is one of the easily structured forms of synthesis and is also known as wave scanning. Instead of simple oscillators, numerous short samples are stored one after the other. The waves are read out by means of envelopes or other modulation tools and thus brought into a variable play order. Depending on the source material, the resulting spectrum is organically gliding, abruptly jumping or even rhythmic. Wavetables are in the original sense so short "samples" which are intended as a loopable single waveform and generated by additive mixture. I would not use the term sample here, as this could lead to confusion, since there are only individual cycles and no "correct" (in the sense of "long") samples.
Frequency modulation synthesis:
Abbreviated FM synthesis, refers to a technical modulation method based on frequency modulation. In the simplest case, the first frequency is frequency-modulated directly by the amplitude of the second oscillator by means of two oscillators.
This form of synthesis is widely used in software and is also referred to as graintable synthesis. The principle is already anticipated thanks to the term Grain: Small, very short sound fragments of an original sound (usually a sample) form the basis for sound production. The sound fragments can be multiplied during the playback process and reassembled in any sequence by changing the pitch and tempo, stretched through loops and thus extended in the sound. The sound design and composition can be done randomly. From an acoustic point of view, it is thus easy to generate novel sounds and variations of common sound material.
Uses Samples to play.