Allen&Heath XONE 92 - Manual (Page 25)

XONE:92 User Guide 25
Filter Type Select
The filters are ‘state variable’. This means that they
provide three simultaneous filter types, high-pass,
band-pass and low-pass. Three large illuminated
switches select which type is active. You can press
any combination together to create different
response types such as ‘notch’ and an interesting
‘all-pass’ effect. The switches are ‘soft switched’ for
live performance, meaning that the audio signal is
ramped between filter states to prevent audible
clicks.
Note that the last selected type is lost when power
is removed from the console. The LPF is always
selected when power is applied.
The graphs below show the effect on the audio
frequency response for the three filter types. The
range of sweep from low to high frequency is shown
together with the effect of adjusting RESONANCE
(one frequency with several resonance settings
shown).
The vertical scale shows the amount of cut or boost
around the normal 0dB operating level. The
horizontal scale shows the change in frequency
from low (bass) to high (treble).
☺
Tip. Take some time to experiment with the
filters before ‘going live’
11 HPF. Press this switch to select the high-
pass filter. Frequencies below the cut-off point are
removed. The cut-off point is adjusted using the
large VCF control. At minimum little effect is heard
as only sub bass frequencies are removed. Sweep
clockwise to gradually remove the bass line followed
by the higher frequencies. The highest frequency is
limited to 10kHz as little useful material is heard
beyond this.
☺
Tip. Use the HPF with the VCF as a mix aid.
Set the VCF control to the nine o’clock position to
remove all the low frequencies when bringing a
track into the mix. Progressively rotate the VCF
control anticlockwise to bring in the bass.
12 BPF. Press this switch to select the band-
pass filter. Frequencies above and below the cut-off
point are removed leaving just a narrow band of
sound. Sweep VCF around its mid position to affect
lead sounds such as keyboard and vocals.
☺
Tip. Try picking out individual sounds such as
vocals and mixing them into the beat and bass of
the opposite track to create a whole new mix. Add a
little resonance to the BPF to lift the sound out of
the mix.
13 LPF. Press this switch to select the low-pass
filter. Frequencies above the cut-off point are
removed. The cut-off point is adjusted using the
VCF control. At minimum only sub bass remains.
Sweep clockwise to gradually introduce the bass
line followed by higher frequencies into the mix.
☺
Tip. Try sweeping the LPF back to a low
setting to keep the beat and energy going while
bringing another track into the mix. Try also
punching in the filter and sweeping it back from high
to low in time with the beat. Punch it out at the start
of the next bar.
In addition to the three basic filter types you can
experiment with new effects by selecting
combinations of switches together. Press and
release the switches together. They illuminate to
show which filter types are active. For example:
HPF+LPF = NOTCH. Used with low settings of
RESONANCE you get a phasing effect. Try
sweeping the effect across the frequency range.
HPF+BPF+LPF = ALL PASS. A surprising effect
considering that all frequencies are ‘passed’.
However, the filter type interaction around the cut-
off point creates an interesting effect that varies
from subtle to dramatic depending on the
RESONANCE setting.
10k 20 1kHz 100 20k
0dB
+5
+10
+15
+20
-5
-10
-15
-20
LO-PASS FILTER
LO HI
BAND-PASS FILTER
LO HI
10k 20 1kHz 100 20k
0dB
+5
+10
+15
+20
-5
-10
-15
-20
10k 20 1kHz 100 20k
0dB
+5
+10
+15
+20
-5
-10
-15
-20
HI-PASS FILTER
LO HI