E-Mu Ultraproteus Operation Manual page 95

Suppose we added yet another dimension to the filter model. We could have the
realtime Morph parameter, the Frequency Tracking parameter (set at note-on
time) and one more parameter, perhaps controlling the amount of the filter
peaks with key velocity. One way to visualize a three-dimensional filter model is
shown by the diagram below.
The Cube filters are actually constructed of eight different complex filters.
Each axis of the three-dimensional cube changes the filter in a different way. In
the example above, key number is being applied to the Frequency Tracking
parameter in order to make the filter frequency track or follow the notes played
on the keyboard. Assigning the keyboard to frequency is called Key Tracking
and is used to keep the timbre of the sound constant as you play up and down
the keyboard. Without key tracking the sound would get duller as you move up
the keyboard and could sound completely different at opposite ends of the
keyboard. Because Frequency Tracking is so important it has been assigned its
own parameter which is used in many of the filters (there are exceptions).
In the filter model above, there is another note-on (defined at the time the note
is pressed) parameter, Transform 2. Unlike the Frequency Tracking parameter,
the effect of Transform 2 may vary from filter to filter. In the example above,
Transform 2 is being used to vary the size of the peaks and notches in the filter.
The frequency plots in the upper plane of the cube have sharper peaks. Key
velocity could be used to control Transform 2 and the sharpness of the filter
peaks.
Frequency Tracking
Frequency Tracking
Frequency Tracking
Frequency Tracking
Key Number
PRESET PROGRAMMING
Chapter 7: Preset Programming
IF THE FREQUENCY GRAPHS AT
THE CORNERS OF THE CUBE ARE
CONFUSING YOU, THINK OF
THEM AS THE SETTINGS ON A
GRAPHIC EQUALIZER.
NOTE: THE FREQUENCY
TRACKING PARAMETER IS
TRANSFORM 1.
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