Clavia Nord Modular V3 User Manual download pdf (Page 202)

8. Synthesis basics: Subtractive synthesis NORD MODULAR V3.0

Page 194

In the first example, the jump happens 5% in from the beginning of the period. This is referred to as a

pulse wave with a 5%

pulse width

(sometimes called

duty cycle

). The second wave has a pulse width of

10%. The third wave has a pulse width of 50%. The third wave is a special case of the pulse wave, called

square wave

, and this has one peculiarity, it only contains odd number harmonics, which gives it a “hol-

low” quality.

On many synthesizers (including the Nord Modular) the pulse width can be adjusted, to set the timbre

of the pulse wave. The more narrow the pulse width, the “thinner” the sound will be.

You can also have the pulse width vary continuously, for example from an LFO or envelope. This is re-

ferred to as

pulse width modulation

(PWM). Modulating pulse widths from an LFO creates a rich, chorus-

like effect often used in “string” sounds.

Above we have only discussed spectra where the overtones appear at perfect harmonics. While this is true

for the basic waveforms discussed above, it is definitely not true for all sounds. If you for example use the

various frequency modulation (FM) or ring modulation capabilities in the Nord Modular, with two os-

cillators set to an “unusual” interval (not octaves or fifths, for example), you will get a spectrum where

90%

10%

Time

Amplitude

10 20 30 40

Amplitude

Harmonic number

(Frequency)

50%

Amplitude

Tim

10 20 30 40

Amplitude

Harmonic number

(Frequency)

1 2 ... 197 198 199 200 201 202 203 204 205 206 207 ... 231 232

No comments

Clavia Nord Modular V3 User Manual Page 202