INSTRUMENTS / GENERATORS
Sytrus - Working with the Harmonics Editor
The operators in Sytrus contain a fully-featured harmonics editor in which you can define an oscillator shape with up to 128 harmonics,
either by drawing the harmonics manually or by analyzing external samples.
An harmonic is a simple sine-wave that is an exact (integer) multiple of the starting frequency (in this case 1,2,3,...128). Harmonic Editors allow
you to perform 'additive synthesis', in which you mix together harmonics (upper facing bars) and adjust their phase (downward facing bars). Using this
technique you can create any type of waveform.
In the example below, a square-wave has been created by adding the first 30 (or so) odd harmonics and adjusting their phase. Bars on the graph may be
Left-clicked and moved up and down to adjust the relative level (upper) and phase (lower) values of a harmonic. After the mix is calculated, the shape
amplitude is normalized to 100%.
- Harmonic Amplitude: The top row sets the number and level of harmonics to be mixed with the shape (order increases from left to right).
Left-click and drag inside the row to add harmonics to the shape. Right-click and drag to draw 'lines' inside the graph. ALT+click to reset the harmonics
levels to neutral position. The scale of the amplitude levels is logarithmic, useful for when you need to add small amounts of a harmonic to the
- Dark bands: To make editing more convenient, darker harmonic levels indicate frequency offsets in octaves (e.g. +1, +2, +3 octaves, etc).
- Harmonic Phase: The lower row sets the harmonic phase (time offset in the range of one oscillator cycle).
- Harmonic frequency: Please note that there are 128 harmonics available. To access higher harmonics use the horizontal scrollbar at
the bottom of the graph (only the first 60 harmonic levels are visible by default). You can also Zoom sections of the graph using the Zoom box
NOTE: Harmonics are only active if the corresponding harmonic has a level higher than 0.
- Keyboard Shortcuts - Lock/Unlock harmonic (CTRL + Left-click), Focus on harmonic (SHIFT + Left-click), Clear harmonic
(ALT + Left-click), Affect multiple harmonics (Right-click + drag across harmonics).
- SMOOTH - Applies smoothing to the levels in the harmonics editor (averaging the levels with their neighbors). When odd/even
harmonics are locked, only they will be smoothed (however, all harmonics will still be considered when computing the average values to apply.
Additional Commands Menu ( )
Click the arrow at the bottom left corner for commands related to working with the harmonics:
- Convert shape to sine harmonics - A sine shape is the default for each operator. This makes working with harmonics easier
and more predictable. You can use this command to convert an oscillator with a non-sine shape to the closest representation of sine wave available.
If the shape is already a sine, this command has no effect.
- Analyze single-cycle waveform - Allows you to analyze ('import') an external sample as an oscillator shape. Please note the
following restrictions: the sample needs to be an oscillator shape ('single cycle' sample), as opposed to sample playback in samplers. Also, keep in
mind that no actual wave sample is importer. Rather, the harmonics of the sample are analyzed and imported as harmonic settings in the Harmonic Editor.
If the sample is too long and/or too complex the import might not be accurate.
- Export single-cycle waveform - Creates a .wav file of the current waveform in the Editor.
- Lock harmonics - Use this to selectively gain control of the harmonic bands. The options are None (default), All, Odd, Even,
Invert and Inactive (note that if this does not appear to lock inactive bands they probably have a very small level not visible in the Editor,).
ALT+ Left-click will clear a band.
- Transpose One Octave Up - This command 'multiplies' the position of the harmonics to shift them up with an octave. Bear in mind
that some information will be lost (for all harmonics and the high end which go out of range /above 128'th harmonic/).
- Shift Left/Right - Shifts the harmonics one position to left/right.
- Smooth up soft/hard - These options smooth the harmonics by a small (soft) or large amount (hard). Designed to avoid waveform clicks.
- Attenuate Gibbs Phenomenon - Applies techniques to attenuate the 'Gibbs phenomenon' as a pre-processing step applied to the harmonic
levels. There is also a runtime 'Gibbs attenuation' option, found in the Main Panel. The 'Gibbs phenomenon' causes ringing around the point of
transition in oscillators with sharp transitions (discontinuous line). You can learn more about Gibbs phenomenon on the internet.
- Remove Gibbs Phenomenon - Removes the 'Gibbs phenomenon'. The 'Gibbs phenomenon' causes ringing around the point of
transition in oscillators with sharp transitions (discontinuous line). You can learn more about Gibbs phenomenon
on the internet.
- Reset phases - Restores the Phase settings to their original state.
- Randomize phases - Randomizes the value of any active phase bars. What did you think it did? :)
- Copy/Paste - Allows you to copy the harmonic settings of an oscillator and paste them to another oscillator. There are
several modes: Replace - the "classic" method in which old data is replaced by that in the clipboard;
Add- sums the existing harmonics with the clipboard; Subtract - subtracts the clipboard levels from the existing
levels; Multiply - Multiplies the existing harmonic levels with those in the clipboard; Blend - sums the
existing harmonics with the clipboard at 50%.