This type of
sound synthesis combines analog access and digital flexibility in a simple way. Although wavetable synthesis is a form of "sample playback" in principle, this term should be avoided because functionality, operation and results are totally different.
A wavetable is a table made up of a number of columns. Each column represents one waveform, that can be either located in the ROM or RAM area of the synthesizer or calculated by an algorithm after selecting the wavetable. For the purpose of using a wavetable inside a sound program, it doesn’t matter what source the wavetable comes from.
A wavetable itself contains no waveform data, but is in fact a collection of pointer entries referencing a number of individual waveforms. Not all columns of the wavetable have to contain entries. When one or several sequential columns contain no pointer, the synthesizer calculates the waveforms for these locations automatically. The algorithm producing these "imaginary" waves uses an interpolation scheme that crossfades the "real" ones. E.g. when a wavetable contains entries in column 1 and 5, the positions 2 to 4 are generated based on interpolation between the existing waveforms in column 1 and 5.
The wavetable can be swept in realtime by modulators like an envelope generator or an LFO .
A number of synthesizers manufactured by Waldorf and formerly by PPG use this synthesis method that are characterized by an "animation" that is very unique. A good example of a Wavetable-type sound would be the bassline from Thomas Dolby's "Windpower".