39. Creating Variations

Create Variation window Figure 39.1
Click on thumbnail for full size image.

Figure 39.1 shows a Variation called NewTwenty, based on an existing Variation called Twenty, being set-up. A Variation in the Kangas Sound Editor is what you can use to allow the amplitude of individual frequencies in a Harmonic or Anti-harmonic to vary over time. For example, there are real life musical instruments where the fundamental frequency out-lasts the harmonic frequencies. A Variation would allow a decay of the individual harmonics to be specified, so that this effect can be achieved. It would also allow mutating effects, ie the tone of the note changing over time.

A Harmonic or Anti-harmonic can optionally refer to a Variation. If no Variation is referred to, the amplitude of individual frequencies will be fixed through-out the lifetime of a sound relative to each other, specifying a Volume graph varies the amplitude of all the frequencies of a Harmonic or Anti-harmonic.

Each row in the table corresponds to a frequency of a Harmonic or Anti-harmonic which refers to this Variation. The ways that a Variation can effect the frequency of the Harmonic/Anti-harmonic follow:

  1. If the zero flag is set, then the amplitude of the corresponding frequency will be zero throughout the duration of the sound, irrespective of other column settings.
  2. The columns Overall offset, Overall duration, and Overall graph work together. Overall offset and Overall duration are in seconds, unless the 'Overall ofs %' and 'Overall duration %' checkboxes are checked, in which case the values correspond to percentages of the duration of the sound. For the period defined by Overall offset (which starts from when the sound starts), the amplitude of the corresponding frequency will be zero. For the period defined by Overall duration (which starts when the period defined by Overall offset finishes), the amplitude can be a fraction of its normal (determined by Volume graph and extent) value, but not greater than its normal value. The actual amplitude is set by the graph in the 'Overall:' field, provided that the 'Overall graph' checkbox is checked. Note that if 'Overall duration' is 0, it is taken to be the entire duration of the sound less 'Overall offset'.
  3. The columns Interval, Initial Interval (numeric field), Duration, Period graph, Interval graph, Duration graph and Initial Interval (checkbox) work together. If the Initial Interval checkbox is checked, then for the period of time defined by Initial Interval, the amplitude of the corresponding frequency will be zero. The amplitude will then follow a repeating pattern; this pattern will repeat every Interval seconds (unless 'Interval %' is set, in which case it is a proportion of the duration of the sound). If the 'Interval graph' checkbox is checked, this interval will not be fixed, it will depend on the graph in the 'Interval:' field (which should yield values > 0), and will be a fraction of the value in the 'Interval' column. The duration of the period is determined in a similar way by 'Duration' (numeric field), 'Duration Graph' (checkbox) and 'Duration:' (graph field), the amplitude graph is scaled over the period set by the resulting duration, which could be greater than or less than the Interval values. Period Graph is effectively the amplitude graph, ie it determines the fraction of the normal value of a frequency over the (repeating) period. There are also a couple of defaulting rules:

    1. If the Duration column value is zero, it will be taken to be the same as Overall duration (see list item 2).
    2. If the Interval column value is zero, it will be taken to be the same as the Duration column value.
    Although all this may sound a bit complicated, this is really just a way to have parts of a sound getting quieter and louder and quieter and louder and so on throughout the duration of the sound.
  4. Note that the functionality in the above 2 list items is not mutually exclusive, ie all column values can be active simultaneously in any given row.