Kurzweil K2500RS, Musician'S Manual

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DSP Functions
Introduction to Algorithm Programming
14-4
UNIPOLAR KEYSTART
The range of values for KStart is C -1ÐC 9 unipolar, and C -1ÐC 9 bipolar. Unipolar and bipolar
values have different effects on the key tracking. The next three diagrams illustrate the effect of
three different
unipolar keystart values on the key tracking curve when a positive value is
assigned for the KeyTrk parameter. At a KStart value of C 4, for example, there is no key
tracking effect below Middle C (it multiplies the key tracking amount by a key number value of
0). The key tracking value is multiplied by 0 at C 4 (normal key tracking), by 1 at C# 4, by 2 at D
4, and so on to a maximum of 64 at 5 1/3 octaves above the KStart value. For higher notes, the
key tracking effect would still increase on its own, but the effect of keystart would not increase
further. At a KStart value of C 3, the key tracking value would be multiplied by 0 for C 3 and all
notes below, by 1 for C# 3, and so on. The key number value would reach its maximum of 64
before reaching C 9. When KStart is set above C 4, its effect on key tracking will continue to
increase up to C 9, but will not reach full scale at C 9.
YouÕll use unipolar values for KStart when you want to cancel the key tracking effect on a DSP
function over a sizable portion of the keyboard, but have it increase or decrease throughout the
rest of the keyboardÕs range. Set high unipolar values for KStart when you want to remove key
tracking from the lower notes, applying it only to the higher notes. If you have set a positive
value for KeyTrk, set low unipolar values when you want to apply key tracking to the lower
notes and pin it at its maximum throughout the upper range of the keyboard. You may want to
use low values of key tracking in this case, depending on the DSP function youÕre applying.
When the value of the KeyTrk parameter is negative, remember that the key tracking is at its
minimum effect at C 9, and maximum at C -1. In this case, the key tracking effect will be
reduced for notes above the KStart setting. For notes below the keystart note, the normal key
tracking amount will apply.
BIPOLAR KEYSTART
For bipolar KStart values with positive key tracking values, the effect on key tracking depends
on whether the KStart parameter is set above or below C 4. When itÕs above, the effect on key
tracking will be minimum at C -1, reaching its maximum effect on key tracking at the keystart
Negative KeyTrk value with
KStart value at C4 Unipolar
C 4 C 3 C 5
Positive KeyTrk value with
KStart value at C 3 Unipolar
C 4 C 3 C 5
Positive KeyTrk value with
KStart value at C 5 Unipolar
C 4 C 3 C 5
Positive KeyTrk value with
KStart value at C4 Unipolar
C 4 C 3 C 5