Allen&Heath GL2400 - Manual (Page 26)

26 GL2400 User Guide
Polarity Refers to the positive (+) and negative (-) wires of a
loudspeaker or balanced audio connection. The console input
channels include POLARITY switches which reverse the + and – input
connections. Some applications include correcting for reverse wired
cables, correcting for microphone placement problems, mixing two
mics on a snare drum, one above the other below where the
diaphragms move in opposite directions, and helping to reduce comb
filtering effects as radio miked actors perform close to each other.
Polarity is sometimes labelled ‘phase’ on mixing consoles.
Technically, ‘phase’ is not the correct term as it implies a 180 degree
time shift. Polarity simply reverses the wires. It does not affect time.
Before starting your mixing, check that all the channel polarity
switches are correctly set, normally up (+).
Mixing the PA in mono or stereo? Because a console
provides an L and R output does not mean you have to mix in stereo.
It is often convenient to have separate fader control, processor inserts,
and outputs to drive two mono speaker stacks in an FOH system.
How much stereo you introduce into your mix depends on where you
position the pan controls. In most situations the size of the room and
position of the speakers makes stereo mixing an advantage only for a
small section of the audience, usually those around the sound
operator! Those listening near the speakers are likely to lose
information from the opposite stack. For this reason it is best to mix
most sources in mono (pan centred). However, it can enhance the
image by mixing some ‘ambient’ sounds in stereo, for example reverb
returns, keyboards and special effects. Where the speakers are
widely placed, you can reduce the stereo image by reducing the
amount of panning to each side. Whatever image you create it is
important that you listen to the results and consider the listeners at all
positions in the room.
Zero the console Before starting the sound check it is good
practice to ‘zero’ the console by setting all its controls to a sensible
starting condition. Set all GAIN, EQ and PAN controls mid, FADER,
AUX and MATRIX controls off, TALKBACK and OSC/NOISE levels off,
and all switches up. Make sure the osc/noise generator is turned off.
Cue Sheets are provided at the rear of this user guide for you to copy
and log your control settings. These can also be downloaded from
our web site.
Turning the system on and off It is good practice to:
• Turn the amplifiers on last and off first.
• Mute channels before plugging cables, unplugging
instruments and switching phantom power.
• Let equipment which has been stored in a damp or cold
place acclimatise in the venue first before powering it up.
• Power up the system in plenty of time before you start the
sound check or show.
Sound levels The ear is a delicate instrument. Do not subject
yourself or any listener to long periods of loud sound, particularly with
extreme equalisation. This may result in frequency selective or full
range hearing loss. Adhere to the sound level regulations which may
apply to the venue… and common sense!
POLARITY
Think before you hit
the switch!
PFL
10 5 0 5 10
20
L-R 1-2 3-4
30
00
23
PFL
10 5 0 5 10
20
L-R 1-2 3-4
30
00
22
PFL
10 5 0 5 10
20
L-R 1-2 3-4
30
00
21
PFL
10 5 0 5 10
20
L-R 1-2 3-4
30
00
20
PFL
10 5 0 5 10
20
L-R 1-2 3-4
30
00
19
PFL
10 5 0 5 10
20
L-R 1-2 3-4
30
00
18
PFL
10 5 0 5 10
20
L-R 1-2 3-4
30
00
24
PFL
10 5 0 5 10
20
L-R 1-2 3-4
30
00
17
32 31 30 29 28 27 26 25
M R L 4 3 2 1
10 5 0 5
30
00
20
10
10 5 0 5
30
00
20
10
10 5 0 5
30
00
20
10
10 5 0 5
30
00
20
10
10 5 0 5
30
00
20
10
10 5 0 5
30
00
20
10
10 5 0 5
30
00
20
10
MTX1 MTX2 MTX3 MTX4
PRE
AUX
AUX
4
3
AUX
AUX 2
1
O O +6
POST
O O +6
O O +6
O O +6
-15
LF -15
+15
+15
180 45 LM 35 Hz 70 -15 400 1k 250 +15
3k
HM 700 50 0Hz
-15
1k 6k 15k 4k +15
HF
GAIN 20 0
HPF 50 40
+48V
30
6 AUX
AUX 5
MUTE
+6 O O PRE POST
O O +6
EQ IN
POLARITY
PRE
AUX
AUX
4
3
AUX
AUX 2
1
O O +6
POST
O O +6
O O +6
O O +6
-15
LF -15
+15
+15
180 45 LM 35Hz 70 -15 400 1k 250 +15
3k
HM 700 500Hz
-15
1k 6k 15k 4k +15
HF
GAIN 20 0 50 40
+48V
30
6 AUX
AUX 5
MUTE
+6 O O PRE POST
O O +6
EQ IN
POLARITY
PRE
AUX
AUX
4
3
AUX
AUX 2
1
O O + 6
POST
O O + 6
O O + 6
O O + 6
-15
LF -15
+15
+15
180 4 5 LM 35Hz 70 -15 400 1k 2 50 +15
3k
HM 700 500Hz
-15
1k 6k 15k 4k + 15
HF
GAIN 20 0 50 40
+48V
30
6 AUX
AUX 5
MUTE
+ 6 O O PRE POST
O O + 6
EQ IN
POLARITY
PRE
AUX
AUX
4
3
AUX
AUX 2
1
O O +6
POST
O O +6
O O +6
O O +6
-15
LF -15
+15
+15
1 80 45 LM 35Hz 70 -15 40 0 1k 250 +15
3k
HM 700 500Hz
-15
1k 6k 15k 4k + 15
HF
GAIN 20 0 50 40
+48V
30
6 AUX
AUX 5
MUTE
+6 O O PRE POST
O O +6
EQ IN
POLARITY
PRE
AUX
AUX
4
3
AUX
AUX 2
1
O O +6
POST
O O +6
O O +6
O O +6
-15
LF -15
+15
+15
180 45 LM 35Hz 70 -15 400 1k 250 +15
3k
HM 700 500Hz
-15
1 k 6k 15k 4k +15
HF
GAIN 20 0 50 40
+48V
30
6 AUX
AUX 5
MUTE
+6 O O PRE POST
O O +6
EQ IN
POLARITY
PRE
AUX
AUX
4
3
AUX
AUX 2
1
O O +6
POST
O O +6
O O +6
O O +6
-15
LF -15
+ 15
+ 15
180 45 LM 35Hz 70 -15 400 1k 250 + 15
3k
HM 700 500 Hz
-15
1k 6k 15k 4k +15
HF
GAIN 20 0 50 40
+48V
30
6 AUX
AUX 5
MUTE
+6 O O PRE POST
O O +6
EQ IN
POLARITY
PRE
AUX
AUX
4
3
AUX
AUX 2
1
O O +6
POST
O O +6
O O +6
O O +6
- 15
LF - 15
+15
+15
180 45 LM 3 5Hz 70 - 15 400 1 k 25 0 +15
3k
HM 700 5 00Hz
-15
1k 6 k 15k 4k +15
HF
GAIN 20 0 5 0 4 0
+48V
30
6 AUX
AUX 5
MUTE
+6 O O PRE POST
O O +6
EQ IN
POLARITY
PRE
AUX
AUX
4
3
AUX
AUX 2
1
O O + 6
POST
O O + 6
O O + 6
O O + 6
-15
LF -15
+15
+15
18 0 45 LM 35Hz 70 -15 40 0 1k 250 +15
3k
HM 700 500Hz
-15
1k 6k 15k 4k + 15
HF
GAIN 2 0 0 50 40
+48V
30
6 AUX
AUX 5
MUTE
+ 6 O O PRE POST
O O + 6
EQ IN
POLARITY
AFL AFL
OO
LEVEL O O R OO
L OO
O LEVEL
O MUTE +6
+6
MUTE O +6
O +6
O
O +6 R
+6 L
O +6
O +6
2
3
GRP 4 OO GRP OO
1 GRP O O
GRP
2
O
O 3 +6 4 GRP
+6 GRP O +6
O +6
O 1 +6 GRP
GRP
O +6
O O EXT O +6 EXT O +6 I N IN
O LEVEL
OO +6
O +6
O
O R
L
O +6
O +6
2
O
O 3
4 GRP
GRP O +6
O +6
O 1 GRP
GRP
O +6
O EXT O +6 IN
O LEVEL
OO +6
O +6
O
O R
L
O +6
O +6
2
O
O 3
4 GRP
GRP O +6
O +6
O 1 GRP
GRP
O +6
O EXT O +6 I N
AFL MUTE AFL MUTE
REV AFL REV AFL AFL REV AFL REV REV AFL REV AFL
AFL AFL AFL AFL AFL AFL
PAN GRP2 GRP1 PAN TO LR PAN TO LR GRP4 GRP3 TO LR TO LR PAN M SOURCE
+16
MONITOR PFL
TALK 0
GRP L-R
1 0 L-R 2TRK
-6 -9 -20
-30 -16 -12 -3 0 +3 +6 +9
OSC/NOISE
TALKBACK
ON
MIN
L
MAX O O
MIN MAX 2TRK REPLAY
TO LR R 2TRK + 10
PHONES
SELECT
1-4 AUX 1-2 AUX 3-4 AUX 5-6
PINK 1kHz
MIC
MONITOR FOH
LINE LINE LINE LINE LINE LINE LI NE LINE (PAD) (PAD) (P AD) (PAD) (PAD) (PAD) (P AD) (P AD)
100Hz 12k
80Hz
12k
80 Hz
12k
80Hz
12k
80Hz
12k
80Hz
12k
80 Hz
12k
80Hz
1 2k
80Hz
P K! +6
0
SIG PK! +6
0
SIG PK! +6
0
SIG PK! +6
0
SIG PK! + 6
0
SIG P K! +6
0
SIG PK! +6
0
SIG
LISTEN WEDGE
AUX 6 MONO (L+R)
HPF 100Hz HPF 1 00Hz HPF 100Hz HPF 100Hz HPF 100Hz HPF 10 0Hz HPF 100Hz
AFL
(AUX FED SUB) L R
=
L R
=
R L R
=
L
=
3 AUX
O O
AUX 1 OO +10 +10 2 AUX 0 0 +10 OO + 10 OO 0 4 AUX
OO +10 OO
AUX 5 0 AUX 0 6 + 10 0
ODD
PAN L EVEN R
=
ODD
PAN L EVEN R
=
ODD
PAN L EVEN R
=
ODD
PAN L EVEN R
=
ODD
PAN L EVEN R
=
ODD
PAN L EV EN R
=
ODD
PAN L EVEN R
=
ODD
PAN L EVEN R
=
AFL
6 -14 40 60 6 -14 40 60 6 -14 40 60 6 -14 40 60 6 - 14 40 60 6 -14 40 60 6 -14 40 60 6 -14 40 60
MODE
MUTE MUTE MUTE MUTE MUTE MUTE
POWER