Dr.Godfried-Willem RAES
Kursus Experimentele Muziek:
Boekdeel 2: Live Electronics
Hogeschool Gent : Departement
Muziek & Drama
2033
Active Filters
The circuit for any 2-order section of a Butterworth,
Bessel or Chebychev filter looks like this:
Filter sections can be simply cascaded to give
4th order, 6th order, 8th order filters.
-
Butterworth filters
should be used if you want maximum flatness within the passband.
-
Chebychev filters should
be used if you want the steepest possible characteristic at the cut off
frequency. The allowable ripple in the passband can be set to 0.5dB or 2dB
(hence the two different compilations).
-
Bessel filters should
be used if phase linearity is an important issue for your application.
We designed simple to use
utilities for the calculation of these types of filters:
The source code is available from our electronics directory
on this site as well. Compilation requires the Power Basic Console Compiler,
version 2.0 or higher.
Filedate: 990107/ Last update 2003-09-16