UTSA Electronic Music Studio Web Site: Basic Wave Shapes

Basic Wave shapes

Triangle: a waveform containing only the odd harmonics - each successively higher harmonic is lower in amplitude than the previous one in the series. Formula: 1/p2. So...

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Pulse: a waveform that alternates between high (+) and low (-) states. Its harmonic content is dependent upon the duty cycle. The duty cycle is expressed as a ratio of the positive portion (usually the shortest portion except in a square wave) to the entire cycle... Example x:y. Further, all harmonics which are multiples of y (including y itself) are missing. The existing harmonics decrease in amplitude at the rate of 1/p. A square wave is an example of a pulse wave with a duty cycle of 1:2 and its decreasing harmonic amplitude structure (1/p) differentiates it from a triangle wave (1/p2). Only odd partials are found in a square wave.
Sawtooth: this waveform contains all harmonic partials of the series at a decreasing amplitude rate of 1/p.
Noise: a complex waveform representing all frequencies at randomly shifting amplitudes.

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