Allen&Heath Qu-16 - Manual (Page 25)

Qu Mixer User Guide 25 AP9372 iss.4
HPF (high pass filter)
The HPF is used to reduce unwanted low frequency
sounds such as vocal popping, wind noise and stage
rumble.
Switch the HPF in using the In key. Use the panel
rotary or screen button and rotary to sweep the cut-off
frequency until you have reduced the unwanted
sound. The filter has a 12dB slope and can be swept
from 20Hz to 2kHz. The violet screen curve shows the
resulting frequency response.
PEQ (parametric equaliser)
The Parametric Equaliser allows tonal adjustment of
the channel sound. It provides independent control of
4 frequency bands:
LF (low frequency)
LM (low mid frequency)
HM (high mid frequency)
HF (high frequency)
Each provides 3 parameters that can be adjusted:
Gain – Boost or cut frequencies by up to 15dB. Centre
0dB is flat response (no affect).
Frequency – Each band can sweep its centre point
frequency across the full range from 20Hz to 20kHz.
This means you can overlap bands and have more
precise control over problem frequency areas.
Width – Each band has a bell-shaped response. The
width of the bell can be varied from a very wide 1.5
octaves affecting many frequencies to a very narrow
1/9
th octave affecting a small range of frequencies.
Setting LF or HF to widest position using the screen
rotary changes its response to shelving.
Experiment with the controls to hear their affect on
different sounds. Switch the PEQ in or out using the In
key to compare the sound. It is better to cut rather than
boost frequencies where possible.
Compressor
The Compressor is a powerful tool for controlling the
dynamics of the sound, for example to smooth out a
bass guitar or to narrow the dynamic range of a vocal
to make it more intelligible in a busy mix. At its extreme
setting the compressor can be used as a limiter to
prevent the signal exceeding a preset maximum level.
A compressor works by dynamically reducing the
amount of gain when the signal increases above a
certain threshold. This pulls back loud moments.
Applying ‘make-up’ gain restores the average volume
and also has the effect of bringing up quiet moments.
The result is a reduced dynamic range.
While listening to the signal adjust Thres (threshold) to
set the point at which compression starts. The GR
indicator and red screen meter will start to show that
compression is active. Set Ratio for how much
compression you want from none (1:1) to full limiting
(Inf). A ratio of 3:1 is a good starting point.
Compressor active
GR = Gain Reduction
Touch the curve to turn the colour
fill option on or off.