SPL Frontliner Modular Recording Channel - Manual (Page 23)

23
Frontliner
VU-Meter
Control Elements
VU meter
The VU meter displays the output level (behind the OUTPUT control). The gauge indicates
levels from -20 dB to +5 dB. If necessary you can lower the sensitivity by 10 dB so that the
gauge goes up to +15 dB output level (see “0 dB/-10 dB” below).
An especially interesting feature is the option to switch between two display modes: VU mode
and PPM mode. The VU mode (VU=Volume Unit) displays average levels, thus provides infor-
mation on the overall loudness. The PPM mode (PPM=Peak Program Meter) displays the peak
levels.
The integration time of the display complies with the BBC requirements, as these characteris-
tics represent ideal conditions for reading both VU and PPM values.
VU/GR switch
With the VU/GR toggle switch you can select if the VU meter displays the output level (VU) or
the gain reduction (GR) caused by compression. In GR mode the needle jumps to the 0 dB mark
and moves from there to the left, the more the compressor takes action. The displayed values
correspond to the level reduction. If the loudest peak causes the compressor to execute a
-9 dB reduction, the MAKE UP control should be set to values around +9 dB to compensate for
(see “MAKE UP” on page 20 for further information).
0 dB/-10 dB switch
With this toggle switch you can change the sensitivity of the VU display. If you select the
-10 dB setting, the sensitivity of the display is lowered by 10 dB. With the needle for example
at 0 dB, a value of +10 dB is displayed. Now you can read values of up to +15 dB, thus read
much higher levels. Switching the VU sensitivity is important with high levels. If you have
for example levelled a signal to 0-3 dB during recording, an EQ processing can easily result
in a level increase above 5 dB – now the sensitivity switch allows to keep following the exact
output level values.
VU/PPM switch
The VU/PPM toggle switch allows to switch the VU metering characteristics from VU display
mode to PPM display mode. The VU mode (VU=Volume Unit) displays average levels, thus
provides information on the overall loudness. The PPM mode (PPM=Peak Program Meter)
displays the peak levels.
A/D converter displays also make use of the PPM mode. Monitoring peak levels is most
important to avoid overloading the converter and to prevent audible distortion. Peak levels
are always above the average levels. At times it may make sense to also select the -10 dB
setting to prevent the needle from getting stuck on the right side of the gauge.
0 dB -10 dB
GR VU
VU PPM
7 5 3 1 0 3 5
30 50 70 100
VU
5 3 1
VU
20
10
0 %
MIC GAIN
S-R
EDUCTION
IN
STR UMEN
T
S- DETECT
AD -OVL
13
1 4
1 5 1 6 1 8 20 2 2 24 26 28 30
33
3 6 3
9 4
2 4
5 5
2 6
1 68
INS
TR. GAIN LINE GAIN RATIO
ATTACK
LMF
MHF
LMF – / +
MHF – / + AIR BAND
TU
BE SATURATIO
N
INSTR.
LINE IN TUBE
+15 dB
ON ON
MUTE
EQ PRE
COMP.
EQ/TUBE COMP.
EXTERNAL INPUTS
DE-ES. AUTO 48 V PAD
R e c o r d i n g C h a n n e l
Ø
MAKE-UP
RELEASE
OUTPUT
Sound Performance Lab Made in Germany
ON
0
-1
-2
-3 -4
-6
-
9
-1 1
-1 2 21
16
11
6
0
-5
-9 - 16 -22 -30
-38
-4
6
-
54
-58 1.2
1 .4
1
.7
2 .0
2.3 2.7 3.0
3
.6
5.0
1
6
∞
0
1 0
2
0
3
0
4 0 50 60
7
0
80
9
0
10
0 -20
- 13
- 7. 5
-4 .5
- 2
0 1.5
3
4
5
5. 5
0.1
0.2
0 .4
1.0
2.5 7.0 16
4
0
1
30
5 30 1
000 0.03
0 .05
0. 09
0 .15
0. 25 0.4 0.65
1
.0
1.3
1
.8
2 .0
0
0
.5
1
2
3
4
5 6 7 8
9
10
1 2 1
4
16 1
9
2 0 -12
- 10
- 5
-2 .5
0 2.5
5
7.5
10
12
-12
- 10
- 5
-2 .5
0 2.5
5
7.5
10
12 -10
-8
-6
- 4
-2
0 2
4
6
8
10
680
8 20
1 k 0
1 k 5
2 k 7 3 k 4 4 k 5
6 k 5
1
0 k
13 k
15 k
30
4
0
5 0
80
125
160 200
3
00
5 00
64
0
70 0
Model 2800
GR VU VU PPM 0 dB -10 dB
THR
ESHOLD
Frontliner
6
8 1 1 1 4 1 7 1 9 2 1 23 25 26 27 29 3
2 3
5 3
7 3
9 4
1 4
2
4 3
-20
-1 8
- 12
-9
0
3
9
10
dB 1:x dB dB
dB dB Hz
Hz %
ms s
dB dB
dB