User Manual

Allen & Heath  15  WZ
4 
16:2 and 12:2 User Guide 
The MONO Input Channel 
+48V   Switches +48VDC to the channel input XLR for powering micro-
phones  or  DI  boxes  that  need  phantom  power.    The  power  is  current 
limited through 6k8 ohm resistors to pins 2 and 3. 
  WARNING:    Do  not  connect  unbalanced  sources  or  ca-
bles to inputs with phantom power selected. To avoid loud 
clicks  always mute  the channel before switching +48V  on or off 
and when plugging or unplugging microphones. 
PAD (LINE)   Press this switch to select the channel TRS jack LINE in-
put.  Release the switch to select the XLR MIC input.  The XLR normals 
through  the  TRS  socket.    With  nothing  plugged  into  the  line  input  the 
switch therefore becomes a PAD for the mic XLR. It attenuates the input 
signal by 20dB for connection to high level microphone or line sources. 
GAIN      Adjusts  the  input  sensitivity to  match  the  connected source  to 
the internal 0dBu operating level of the channel.  Provides a variable 50dB 
range from +10 to +60dB gain (mic), or -10 to +40dB (line, pad selected). 
The  gain  should  be set  using PFL  so that  the console  meters average  ‘0’ 
with loudest moments lighting ‘+6’.  Reduce gain if the red peak indicator 
lights. 
HPF Switches in the channel high pass filter. This attenuates frequencies 
below 80Hz by 12dB per octave.  The filter is pre-insert, pre-EQ.  Select 
the HPF to reduce low frequency noise such as microphone popping, stage 
noise and tape transport rumble. 
EQ   A 4-band semi parametric EQ provides independent control of four 
frequency bands.  HF and LF are shelving filters which affect high frequen-
cies above 12kHz, and low frequencies below 80Hz respectively.  HM and 
LM are bell shaped peak/dip filters which affect frequencies around a cen-
tre  point which can be  swept from 500Hz  to 15kHz and  35Hz  to 1kHz 
respectively.  These have a width (Q) of 1.8.  All bands can be boosted or 
cut by up to 15dB and have a centre detent 0dB position. 
Check for the best microphone selection and placement before using the 
EQ.  Start with the EQ set flat and apply only as much boost or cut as is 
really needed. The EQ IN button can be used to compare the EQ with a 
flat  response.  When  dealing  with  problem  frequencies  cut  rather  than 
boost where possible. 
180
45
35Hz
70
400
1k
250
(LINE)
3k
700
500Hz
1k
6k
15k
4k
HPF
+48V
PAD
SIG
10
5
0
5
10
30
20
+6
+6
+6
+6
1
AUX
2
AUX
3
4
AUX
AUX
PRE
+6
+6
RL
PFL
MUTE
5
AUX
AUX
6
PAN
PK!
POST
POST
10- 10
GAIN
20
0
4060
50
40
30
HF
HM
LM
LF
EQ IN
OO
OO
OO
OO
OO
OO
OO
20k10k5k2k1k5002001005020
-20
-15
-10
-5
0dB
+5
+10
+15
+20 +20
+15
+10
+5
0dB
-5
-10
-15
-20
20 50 100 200 500 1k 2k 5k 10k 20k
10k5k2k1k500200100502010
-40
-35
-30
-25
-20
-15
-10
-5
0dB
+5
20k10k5k2k1k5002001005020
-20
-15
-10
-5
0dB
+5
+10
+15
+20










