What Is A Filter; Low Pass - E-Mu XK6Xtreme Keys Owner's Manual

What is a Filter?

118 E-MU Systems
Most sounds are complex waves containing 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 lets the low frequencies pass and removes only the
high frequencies as illustrated in the following diagram.
100
80
Output of Filter
60
40
20
40
A filter that lets only the high frequencies pass is called a high-pass filter as
illustrated in the following diagram.
100
80
60
40
20
40
Cutoff Frequency
80 160 360 720 1440 2880
Frequency
Initial Frequency
Filter Output
80 160 360 720 1440 2880
Frequency
Programming Basics
Dynamic Filters

Low Pass

Filter
...
High Pass
Filter
...