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Programming Examples
Example 2
To make the stab sound realistic, we'll drop the amplitude at the same rate as the pitch. To do
this, select the F4 AMP page (press the more> soft button once, then press the F4 AMP soft
button). Select the Adjust parameter, and assign a value of 8 dB. This will give the trumpet a bit
more punch. Next, select the Src1 parameter, and set its value to ASR1. Then select the Depth
parameter and set its value to -68 dB.
Here's an important point to remember: ASR1 is being used to control both the drop in pitch for
the stab, and the drop in amplitude as well. All of the control sources can be similarly assigned
for as many parameters as you like.
The final step in this example is to set the velocity threshold of the stab. Right now the stab is
occurring on almost every note, but we want it to happen only when playing fortissimo or
louder. To do this, press the more> soft button three times, then press the VTRIG soft button to
select the VTRIG page. The VTrig1 Level parameter is already selected, so just turn the Alpha
Wheel until the VTrig1 Level value is ff. Now you can play softly without triggering the stab.
That's it for Example 1. If you want to save your work, the easiest way is to press EXIT. The
K2500 will ask you if you want to save. You should probably press the Rename soft button, give
your program a new name, then save it with a new ID. See Chapter 5 if you need help with the
Save dialog.
Example 2
Lowpass Filter, Envelopes
This example will show you how to assign a DSP function to an algorithm block (the 4-pole
lowpass filter), and adjust its control parameters. You'll also set up an envelope to control the
cutoff frequency of the filter.
Start with Program 199, press EDIT, and select the KEYMAP page (This is explained in a bit
more detail in the previous example, if you haven't read it). Change the value to "6 Ensemble
Strings." String sounds are especially responsive to lowpass filtering, because they have a great
deal of activity in the higher frequencies. Lowpass filters, depending on their cutoff
frequencies, attenuate high frequencies, so a bit of adjustment can alter a string sound
considerably.
Next, press the ALG soft button to select the ALG page. The center DSP function block will
already be selected. Set its value to "4POLE LOWPASS W/ SEP." Notice how the sound
changes. Press the more> soft button, and the three soft buttons that select the control input
pages for the lowpass filter will appear. Press the F1 FRQ soft button.
The Coarse Adjust parameter will already be selected. Try a few different values for this
parameter, to get a feel for its effect on the sound. Then set it to a value of G#3 208 Hz. Use the
cursor buttons to select the Src1 parameter, and set its value to MPress (3, 3, ENTER). Cursor
down once to the Depth parameter, and set it to a moderate value, like 3800 cents. Now try
playing and applying pressure to the keys. (Obviously, this will have no effect if your MIDI
controller doesn't send mono pressure.)
Now we're going to use an envelope to control the sweep of the filter. The K2500 has one
envelope dedicated to shaping the output of the sound; this is called AMPENV. However, two
other envelopes (ENV 2 and ENV3) can be assigned to control other parameters. You can assign
AMPENV as a Control Source, but using ENV2 and ENV3 lets you assign separate envelopes to
do different things.
Cursor down to the Src2 parameter, and set its value to ENV2 (1, 2, 1, ENTER). Cursor down to
the DptCtl parameter and set its value to ON. Cursor down to the MaxDpt parameter, and set
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