Subtractive Synthesis (2)
Oscillators and Waveforms
Oscillators - An Oscillator generates a sound. It actually generates a waveform or a shape. The oscillator does this continuously. The rate at which it generates each cycle of the waveform is what we hear as pitch. Pitch is measured in Hertz (Hz) (where one Hertz is one cycle per second).
There are may types of oscillators but the main “oscillator” usually refers to a “Keyboard-controlled oscillator”. On a synthesizer, the keyboard-controlled oscillator may be labeled as VCO (Voltage-Controlled Oscillator), DCO (Digitally Controlled Oscillator), or sometimes as waveform.
All this means is that when you play a note on the keyboard, the oscillator will generate the waveform (or shape) at that intended pitch continuously (for as long as you hold down that note on the keyboard). If you pressed “A3” (the note “A” just below middle “C”), the waveform will be generated at a rate of 440Hz (ie. 440 cycles a second). In short, the keyboard controls the pitch of the oscillator (hence, keyboard controlled oscillator).
A waveform (or wave) is a shape which the oscillator generates. The shape determines the “timbre” or quality, characteristic or brightness of a sound. While pitch tells us which note is being played, “timber” tells us which instrument is being played. While pitch is a basic frequency which identifies the note, “timber” is made up of many other frequencies or overtones which gives the instrument its overall character and identity.
< Copyright ⓒ The Music Telegraph :: Prohibit reprinting and redistribution >
Synthesizer Related Articles
MIDI (popular articles)