Wavetable Synthesis

A table of single-cycle waves lets the timbre slide while you play.

Related

TimbreWavetable synthesisThe software synthesizerModern

The question

A fixed waveform can only be reshaped by a filter, so can the wave morph? Wavetable synthesis lines up single-cycle waves and lets the timbre slide.

How it works

A wavetable stores single-cycle waves, not seconds of audio; each frame holds one period. Playback reads one frame at the played pitch and interpolates between frames by position. Position can be pushed by an LFO, envelope or velocity, so a held note moves from soft to sharp, or from square toward metal. Tables must be band-limited or high notes alias. Several detuned wavetable oscillators widen the stereo image.

Settings and what you hear

The table sets the family, position the current frame, and scan amount and rate how far and fast it travels. A slow scan breathes, a fast one sways, and a hard jump steps digitally. Detune and unison widen the sound, while the filter trims an over-bright top.

What to listen for

Hear the passage where the lead changes colour and ask whether it slides or jumps. Then hear the metallic cave bed and judge whether brightness follows the section. Finally hear the sweeping pad and focus on the wave changing rather than on a filter sweep.

Common misconceptions

That a wavetable is a sample, when a sample is long audio and a wavetable is single cycles; that wavetables belong only to dance music, when they also make quiet beds; that more tables are better, when a wrong table scanned hard only moves the wrong way.

Sources

• Curtis Roads, The Computer Music Tutorial — wavetable synthesis checked, not quoted
• Udo Zölzer, DAFX — Digital Audio Effects, wavetable and interpolation chapter — background checked, not quoted

Used for fact-checking only; all prose is original.