Planet Phatt Operation Manual
44
PROGRAMMING BASICS
Most of the instruments on Planet Phatt are complex waves contain-
ing many sine waves of various amplitudes and frequencies.
A filter is
a device which allows us to remove certain components of a sound
depending on its frequency.
For example, a Low Pass Filter, one of
the Z-plane filter types in Planet Phatt, lets the
l
ow frequencies pass
and removes only the high frequencies.
The point at which the frequencies begin to be cut is called the
Cutoff
Frequency
(or Fc for short). A filter that let only the high frequencies
pass would be called a High Pass filter. Using a filter, we now have a
way to control the harmonic content of a sampled sound. As it turns
out, a low pass filter can simulate the response of many natural
sounds.
For example, when a piano string is struck by its hammer, there are
initially a lot of high frequencies present. If the same note is played
softer, there will be fewer of the high frequencies generated by the
string. We can simulate this effect by routing the velocity of the
keyboard to control the amount of high frequencies that the low pass
filter lets through. The result is expressive, natural control over the
sound.
The auxiliary envelope generator is commonly used to control the
cutoff frequency of the Z-plane filter. This allows the frequency
content to be varied dynamically over the course of the note.
Dynamic filtering coupled with all the different instruments available,
makes for almost endless possibilities in the final sound. Any modula-
tion source can be used to modulate the filter.
••• The initial filter Fc and
all Fc modulators ADD
algebraically to determine
the actual Fc. If you are not
getting sound, adjust the
initial Fc or reduce the
amount of modulation.
Careful adjustment of all the
filter parameters is the secret
to getting great sounds.
20
40
60
80
100
40
80
160 360 720 1440 2880
Frequency
...
Amplitude
Output of Filter
Cutoff Frequency
Содержание Planet Phatt
Страница 1: ...OPERATION MANUAL E mu Systems Inc Fhlanett Phatt ...
Страница 9: ...1 Chapter 1 Basic Setup INTRODUCTION BASIC SETUP ...
Страница 10: ...Planet Phatt Operation Manual 2 ...
Страница 17: ...Chapter 2 Basic Operation 9 BASIC OPERATION ...
Страница 18: ...Planet Phatt Operation Manual 10 BASIC OPERATION ...
Страница 27: ...Chapter 3 Master Menu 19 MASTER MENU ...
Страница 28: ...Planet Phatt Operation Manual 20 MASTER MENU ...
Страница 43: ...Chapter 4 Programming Basics 35 PROGRAMMING BASICS ...
Страница 44: ...Planet Phatt Operation Manual 36 PROGRAMMING BASICS ...
Страница 63: ...Chapter 5 Edit Menu 55 EDIT MENU ...
Страница 64: ...Planet Phatt Operation Manual 56 EDIT MENU ...
Страница 88: ...Planet Phatt Operation Manual 80 EDIT MENU ...
Страница 89: ...Chapter 6 Step By Step 81 STEP BY STEP ...
Страница 90: ...Planet Phatt Operation Manual 82 STEP BY STEP ...
Страница 103: ...Chapter 7 Reference Section 95 REFERENCE SECTION ...