Fundamentals of Synthesizer Programming Ch. 2 - Sources Flashcards
What does an oscillator do?
generates a repetitive electronic signal in the form of a periodic waveform
What two properties of sound does a waveform represent?
pitch/frequency and shape/timbre
What are the three oscillator controls for pitch?
- fine tune (detune)
- coarse tune
- octave selector
What does fine tune do?
adjusts the pitch of an oscillator by small intervals over a short range
Coarse tune adjusts the pitch of an oscillator by _____ _____ over a _____ _____.
larger intervals, wider range
What oscillator control changes pitch by octaves?
octave selector
What interval does the fine tune control change pitch by?
cents
The coarse tune control changes pitch by _____.
semitones
What is the range of the coarse tune control?
one to several octaves
What is the range of the fine tune control?
half or whole step
What is the range of the octave selector control?
four or more octaves
What are the oscillator controls for harmonic content?
- waveform selector
- pulse width
What are the 5 main types of waveforms?
- sine
- triangle
- square
- sawtooth
- pulse
What is a sine wave?
pure tone containing only fundamental frequency
What types of waves contain odd harmonics only?
triangle and square
What type of wave contains odd and even harmonics?
sawtooth
What does a pulse wave do?
varies by shape and harmonic content using pulse width control
What does changing pulse width change?
duty cycle
What is duty cycle?
relative time that waveform is on during one cycle
What does a triangle wave sound like?
brighter, fuller, and louder than sine wave
What does a square wave sound like?
brighter and louder than a triangle wave
What does a sawtooth wave sound like?
bright and buzzy
What is pulse width modulation?
controller such as LFO affects pulse width, causing a thicker sound that varies at the rate of the LFO
What does a noise generator (NG) do?
generates random noise that includes all frequencies
What is the control on a noise generator?
noise color
What does noise color do?
changes the overall spectrum of noise
White noise has equal energy per _____.
bandwidth
Pink noise has equal energy per _____.
octave
For pink noise, _____ increases as _____ increases.
amplitude, frequency
What is beating?
periodic fluctuation in loudness caused by slightly detuning two oscillators
What are three advanced oscillator functions?
- hard sync
- ring modulation
- frequency modulation
What does hard sync do?
allows you to change timbre by forcing one oscillator to restart its cycle in sync with the start of the other oscillator’s cycle
What does ring modulation do?
combines frequencies from 2 oscillators to produce a new audio signal that contains sum and difference frequencies of the 2 original frequencies
If two oscillators produce sine waves at 250 Hz and 600 Hz, the output of the ring modulator would be sine waves at _____ and _____ Hz.
850, 350
What kind of sound does ring modulation produce and why?
metallic, bell-like timbres since the harmonics may no longer be integer multiples of the fundamental frequency
What is frequency modulation?
one oscillator (modulator) becomes the control signal for another oscillator (carrier)
The audio output from a carrier includes its _____ and _____.
frequency components, complex sideband frequencies above and below that frequency
What are sideband frequencies in frequency modulation?
(sums and differences of the carrier + (modulator frequency x sideband number))
As sidebands move further from the carrier frequency, amplitude _____.
decreases
What does FM amount control?
allows you to adjust sidebands; increasing amount increases amplitude and number of sidebands
What does FM sound like?
produces even more complex bell-like tones than ring modulation
