Operator`s manual

Version 1.21 109

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These harmonics combine to create more complex waveforms or sounds and the rule of thumb is

that the brighter the sound, the more harmonics it has (and/or, they are louder in respect to the

fundamental frequency). By manipulating these harmonics with a filter, you can transform the tone

timbre

of a sound.

Another way of looking at a sound is shown below. A typical synthesiser sawtooth wave would look

something like this if analysed (a brass instrument or strings or any other strident sounding instrument

may look similar):

HARMONICS

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FUNDAMENTAL

There is the FUNDAMENTAL (i.e. the pitch of the note being played) and there is the series of

harmonics or overtones. In the case of a sawtooth wave, the first harmonic is twice the pitch or

frequency of the fundamental, the next is three times, the next four, then five, six, etc.. Each

harmonic is proportionally lower in level. In other words, the sound contains an equal spread of

odd and even harmonics.

A ‘true’ square wave such as you’d find on any synth comprises only odd numbered harmonics

(i.e. the harmonics are 3, 5, 7, 9, etc. times the fundamental). E.g.:

HARMONICS

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FUNDAMENTAL

This gives the characteristic ‘hollow’ sound of not only a synth square wave but also clarinet and

other woodwind and ‘pipe’ sounds.

Both of these sounds are bright because you can hear all their harmonics. If you remove some of

these harmonics, however, their tone will change. The following, for example, would sound duller

or more muted than the sawtooth wave shown at the top of the page:

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