wavetable

Wavetable refers to a method of digital audio synthesis in which a collection of periodic waveforms is stored in a table called a wavetable. Each waveform represents one cycle of a periodic signal, usually with different harmonic content. A wavetable oscillator reads the samples from the table to generate an audio signal. By selecting a waveform and moving through the table over time (scanning) or by morphing between adjacent waveforms, the timbre evolves while the pitch remains constant.

Implementation notes: To play notes at different pitches, the oscillator reads through the table at varying rates; to avoid artifacts when the pitch is high, many designs employ interpolation between samples and optional anti-aliasing. Some systems also interpolate between neighboring waveforms in the table to create smooth timbre transitions.

History and usage: Wavetable synthesis originated in the 1980s with digital instruments such as the PPG Wave, which stored multiple single-cycle waveforms in ROM and scanned through them to produce evolving tones. It later appeared in hardware and software instruments from providers like Waldorf, and in contemporary software synths such as Xfer Records’ Serum. Modern wavetable libraries can contain thousands of waveforms generated algorithmically or sampled from real instruments, and many digital audio workstations offer built-in wavetable capabilities.

Applications and limitations: Wavetable synthesis excels at dynamic timbres with evolving harmonic content, from bright leads to evolving pads. Limitations include potential aliasing at high pitches, increased memory requirements for large wavetable banks, and the need for careful design to avoid abrupt timbral changes during scanning.

See also: wavetable oscillator, spectral synthesis, digital synthesis.