User manual

7User Guide Action Filter 4
EN
What did you buy after all?
Action Filter 4 is an analog stereo filter designed to mainly process complex audio sources. This
means, full tracks or loops will be processed entirely. Be it in a DJ-setup or during studio productions,
the Action Filter 4 is a lot more effective and versatile than typical Kill-EQs. We chose the word
“action” in the unit’s name because the filter is always operated manually. There is neither MIDI-
nor control voltage (CV) automation. Thus, the Action Filter 4 demands and supports your intuition
and creativity.
A lter - what‘s that?
Before describing the functions of the Action Filter 4‘s knobs and switches, let’s take a closer look at
filters and what you could do with these.
A filter is an element that carves out specific portions of an original source. This deadpan theoretical
explanation is true for every filter: coffee-filters, color-filters or audio-filters. While colors and
coffee are sometimes topics during lunch break, we are, of course, interested in filtering audio
sources.
Up with the lowpass
Filters are differentiated by two basic types: low- and highpass. These names self-explain the
operation methods. A lowpass filter will only let low audio frequencies pass. The highpass does the
opposite: It only lets high frequencies pass.
The question now is: Which high respectively low frequencies? Who’s in control? Good news - it’s
you! The CUTOFF control allows setting the cutoff-frequency - the point from which the filter starts
working. For a lowpass filter this means: the lower CUTOFF is set, the stronger the suppression
of high frequencies, meaning that the sound gets more muffled. Ergo, the highpass filters works
inversely: the higher CUTOFF is set, the stronger the suppression of lower frequencies, meaning
that the sound loses bass.