Sound Performance Lab 2595 - Manual (Page 24)

24
Passeq
Active EQs
The filters of an active network require external power which allows for an integration of
amplifying elements that allow for both boost and cut functions.
Active EQs dominate the market, and perhaps a good part of this is due to their user friendly
capacity to combine both boost and cut features into single controls. A very good active filter
designs can often offer very responsive characteristics with relatively little signal coloration
or alteration. But the operative word here is “can”—the sonic result of filtering comes under
the influences of so many parameters that it is almost impossible to fullfill any such claims
made categorically.
Parametric EQs
With a fully parametric EQ, all filter parameters are adjustable: The frequency, amplitude and
bandwidth of each filter can be adjusted by a user. The fully parametric EQ is therefore ideally
suited to working very specific or in very narrow limits at any desired frequency. There is also
the case of semi- or half-parametric filters, whose bandwidth is fixed, usually at around two
octaves.
Graphic EQs
For working with the entire audible frequency range, there are available certain fixed
frequency and bandwidth active filters. One can only alter the amplitude of each filter.
Because the designs of such machines originally employed fader controls (and often continue
to do so), these adjusted faders represent in a graphic curve the frequencies and amount of
alteration, and thus earned the name, graphic EQ.
The Basics of Frequency Filtering