Operating Manual - PROTEA SYSTEM II 4.24D Distribution / System Processor
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relatively easy, but finding the best combination of cut and bandwidth takes a little practice. Again, it is well worth the
time getting comfortable with the notching procedure, so that problems can be quickly addressed with a sufficient but
minimal amount of correction.
The EQ functions on all four inputs and eight outputs are switched in or out on an individual channel basis. In
other words, each input or output has one "switch" for all of its EQ filters. If certain filters are not going to be used
within a channel, simply leave the gain for that filter at 0.0dB, and the filter will have no effect.
7.4e Routing
Any of the four inputs can be equally routed, post
input gain/EQ, to any or all of the eight output channels.
Click on the <Routing> box for a given input and select
the desired outputs from the list of check boxes. Color
coded connect lines provide a visual image of the 4.24D
routing scheme.
7.4f HPF/LPF
Bandpass or crossover functions on the Protea
4.24D are available only on the eight output channels.
Every channel's crossover consists of a high pass filter
(HPF) and a low pass filter (LPF), along with the frequen-
cies and filter types used. Each output's crossover sec-
tion is essentially a bandpass filter, making it necessary
for the user to map out ahead of time which outputs will
be used for the various frequency bands, and set the over-
lapping filter frequencies and types accordingly. Note:
The HPF determines the lower frequency limit of the sig-
nal, while the LPF determines the upper frequency limit.
The frequency range for the high pass filter (HPF) is from 19.7Hz to 21.9kHz, with an option to turn the filter
off at the low end of the frequency selection. The low pass filter (LPF) offers the same frequency range, with the "off"
option at the high end of the frequency selection.
There are eleven types of filters available in the crossover section, each suited to a specific preference or
purpose. The slope of each filter type is defined by the first characters in the filter type, 12dB, 18dB, 24dB, or 48dB
per octave. The steeper the slope, the more abruptly the "edges" of the pass band will drop off. There is no best filter
slope for every application, so experiment to see which one sounds most pleasing in a specific system. The Ashly pre-
loaded presets all use 24dB/octave filters in the crossover section, but of course they can be changed to suit the
application.
