Specifications

Operating Manual - ne24.24M Matrix Processor
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Protea ne24.24M parametric lters have a boost/cut range of +15dB to -30dB. There is more cut than boost because one
of the more common uses for parametric lters is to dramatically cut, or “notch out”, very narrow frequencies (low bandwidth)
in order to eliminate system feedback problems. Every parametric EQ lter has a center frequency. The factory default is 1kHz,
but each lter is adjustable from 20Hz to 20kHz in 1Hz steps. Carefully sweeping a narrow bandwidth lter through a problem
feedback area, with just a slight boost, is a quick way to nd the exact frequency causing feedback trouble. Once the offensive
frequency has been found, cut the lter’s level, and then adjust the bandwidth as narrow as possible while still eliminating the
feedback problem. Bandwidth is adjustable from about 1/64 octave to four octaves, and the lower the bandwidth (higher Q), the
less audible the lter action will be. Finding the problem frequency is relatively easy, but nding 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 sufcient but minimal amount of corrective EQ.
All Pass lters: All pass lters have no effect on frequency amplitude, but rather are used to adjust the phase response
of the signal at a given frequency, and are often used in conjunction with a frequency-domain lter to correct phase changes.
At low frequencies, there is 0 degree phase shift, at the All Pass lter center frequency there is -180 degrees of phase shift, and
at high frequencies there is -360 degrees of phase shift. Each input channel has an EQ On/Off button for all lters, and in turn
each lter band has its own bypass button. The Flatten Curve function returns all lters to 0dB, but preserves the frequency and
bandwidth of any used lters.
8.1i Noise Gate
Noise gates are used to minimize unwanted or ambient low level signal
from an individual mic input. THRESHOLD is the level above which an input
signal will pass through, and below which its signal is turned off. RANGE is
the amount of attenuation in dB which the noise gate attenuates the signal when
the gate is off. ATTACK and RELEASE control the time characteristics of the
gating action. Attack sets the amount of time it takes for the gate to open or
gated signal to turn on. Release sets the time required for the gate to close back
up when the input signal falls below threshold.
8.1j Autoleveler
An Autoleveler is a dynamics
processor used to automatically boost
or cut a signal to a user dened target
level. TARGET LEVEL is the primary
setting in an autoleveler, as it determines
the desired constant level to which an
input is boost or cut. Both basic mode
and advanced mode utilize the target
level control, but basic mode simplies
setup. In BASIC MODE, target level, action, and maximum gain are the available con-
trols. ACTION is selectable to gentle, normal, or aggressive, and automatically adjusts
the following controls found in advanced mode:
Action Ratio Hold Time Gain Incr. Rate Gain Dec. Rate
Aggressive 10:1 0 Sec 20ms/dB 5 ms/dB
Normal 4:1 1 Sec 50ms/dB 10 ms/dB
Gentle 2:1 2 Sec 100ms/dB 20 ms/dB
MAXIMUM GAIN controls the threshold below target using the following
formula:
Thr = Max Gain / (1/Ratio - 1)
In ADVANCED MODE, THRESHOLD BELOW TARGET determines the input
signal level relative to the target level, above which the autoleveler increases gain, and below which no action is taken. RATIO
is dened as the relationship of input level change in dB to output level change in dB. It is a measure of how aggressively the
autoleveler changes the gain to maintain a constant output target level. GAIN INCREASE RATE and GAIN DECREASE RATE
are used to prevent sudden, choppy sounding level changes to an input signal having a wide dynamic range. HOLD TIME is