Specifications

Operating Manual - 24.24M Matrix Processor

9.1f Input EQ

The Protea 24.24M input EQ section offers 15 custom filters per input. Types of filters available for each band

include parametric, 1st order and 2nd order low shelf, 1st order and 2nd order high shelf, and all-pass.

Shelving EQ filters: 1st order filters use a

gentle 6dB per octave slope, while 2nd order fil-

ters use a 12dB per octave slope for a more pro-

nounced boost or cut. All shelving filters have a

boost/cut range of +/-15dB. Low shelving filters

have a frequency range from 20Hz through 2kHz,

and the high shelving filters range from 3.886kHz

through 20kHz. Shelving filters are most useful

as broad tone controls to boost or cut the high

end or low end of an audio signal's frequency con-

tent. Because they affect a wider spectrum of au-

dio, they are not as suitable for feedback control

as parametric filters. Course and fine tuning of

shelving filters can be performed using <page up/

page down> and the <up/down arrows> on the

keyboard.

Parametric EQ filters: These are peak fil-

ters with the ability to control boost or cut, fre-

quency center, and bandwidth, also called “Q”

for this type of filter. Think of one band of para-

metric EQ as a single graphic equalizer fader ex-

cept that the frequency is variable, not fixed, and

that the bandwidth, or how "wide" the filter af-

fects the frequency spectrum at the center fre-

quency, is completely variable. The smaller the

bandwidth (higher Q), the less the audio signal

on either side of the frequency center is boost or

cut, whereas a larger "wider" bandwidth (lower

Q) produces an audible change to the overall tone