Allen&Heath Xone 23C - Manual (Page 15)

15
FILTER REFERENCE
The VCF Filters
A voltage controlled filter is an audio filter where the cut-off frequency is altered by a DC
control voltage rather than a variable resistor. This produces a much wider operating
range and more control over the filter response to create unlimited combinations of
tonal effect.
Filter Type Select
The filters provide two simultaneous filter types: high-pass, and low-pass. Large
illuminated switches select which type is active.
The graphs below show the effect on the audio frequency response for the two filter
types. The range of sweep from low to high frequency is shown together with the effect
of adjusting RESONANCE.
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).
10k 20 1kHz 100 20k
0dB
+5
+10
+15
+20
-5
-10
-15
-20
HI-PASS FILTER
LO HI
10k 20 1kHz 100 20k
0dB
+5
+10
+15
+20
-5
-10
-15
-20
LO-PASS FILTER
LO HI