Ashly digiMIX18 - 4.2 PEQ Parametric EQ

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Operating Manual - digiMIX18 Digital Mixer
7) Adjust PEQ (sec. 2.41), expander/gate (sec. 2.43), and compressor/limiter (sec. 2.44) on each input channel as needed. For
greater details and examples of how to use these functions, see sections 4.2, 4.4, and 4.5.
8) Congure the aux1-8 output(s) for all used input channels, adjusting their level to each monitor mix. (sec. 2.12)
9) Apply effects to input channels if desired. See sections 2.13, 2.45, and 4.8 for FX details and examples.
10) Adjust GEQ graphic equalizer for main L/R or aux1-8 outputs. (sec. 2.42)
11) To create a DCA level or mute group for all vocals or other groups, follow instruction in section 2.16, then select the DCA
group before using the fader or mute button.
12) Save settings as scene presets, DSP channel presets, FX presets, or GEQ presets. (sec. 2.31)
4.2 PEQ Parametric EQ
Press the PEQ button to engage the parametric EQ for the
currently selected input channel, main L/R output, FX1-2,
or aux1-8 output. The four lters EQ1-EQ4 can be shelving
or parametric, with additional hi-pass and low-pass lters.
Shelving Filters: EQ1-EQ4 can be set as tuneable shelving
lters, typically used as the high and low boost/cut controls.
Press the lter <Type> image on the touchscreen to toggle
between low shelf, high shelf, or parametric peak lter.
Parametric Filters can adjust frequency, bandwidth (Q),
and lter gain/cut. Think of one band of parametric EQ
as a single graphic equalizer fader where the frequency is
variable, and the bandwidth (Q) is also variable. The smaller
the bandwidth, the less the audio signal on either side of the
frequency center is boost or cut, whereas a wider bandwidth
produces a more audible change to the overall tone of a signal.
In addition to basic tone controls, parametric lters are ideal
for eliminating problem feedback frequencies without greatly affecting the overall sound. They are also useful for adding or
removing a characteristic hot spot from microphones or for precisely compensating for room resonance. It is well worth the
time becoming procient with parametric EQ lters, as they offer the best solution to many EQ problems.
HPF/LPF: The hi-pass and low-pass lters are cut only, with adjustable frequency and slope. There are 20 different lter types
to choose from including Butterworth, Bessel, and Linkwitz-Riley, with lter slopes ranging from 6db/oct to 48dB/oct. These
lters are typically used to limit bandwidth. A common application is to use an aux output to drive 70V transformer tapped
speakers that are not suited for signal below 80Hz. Set the HPF for that aux output to 80Hz, then select the desired lter type.
Tone Control: The four EQ lters can be used as basic tone controls with tuneable frequencies, ie high, high-mid, low-mid,
and low. High and low typically use shelving lters. Press the <Flat EQ> button to restore all lters to 0dB gain, medium Q,
and default starting frequencies and lter types. A lower Q broadens the lter to have a much greater effect, while a higher Q
narrows the bandwidth and makes less of an overall difference when boost or cut.
Notch EQ for Feedback Control: To eliminate a feedback problem on a live mic input, set the PEQ at and turn up the mi-
crophone level until it is on the edge of feedback. Then using the frequency control, sweep a narrower bandwidth (higher Q)
lter through a problem feedback area, with just a slight amount of gain on that lter, until nding the exact frequency causing
feedback. Once the feedback frequency has been identied, reduce the lter's gain until feedback is gone. Adjust the bandwidth
(Q) as narrow as possible while still eliminating feedback. Repeat with additional lters and frequencies as necessary. Finding
the problem frequency is relatively easy, but nding the best combination of minimal cut and bandwidth takes a little practice.
Notch EQ for Room Resonance: To reduce excess reverberation or boominess in a room, use the parametric lter on the main L/R
or aux1-8 outputs. With music playing through the speakers, engage a PEQ lter on the output, then sweep the lter's frequency
with a slight boost and medium Q until you hear a disproportionate increase in the boominess of the music. This frequency is a
room resonance, and can be notched to compensate. Adjust the bandwidth and cut only as little as necessary to x the problem.
Figure 4.2: PEQ Parametric EQ Screen