Nilfisk-ALTO ACL2 Pro - Manual (Page 8)

5. Threshold Control
This control adjusts the threshold level for the Compressor section in the range of -40dBu to +20dBu. The SKC
(Smart Knee Control) is applied to the audio signal, which is a maximum of 10dB above the set threshold.
Above such level (10dB) a hard knee compression will be applied.
6. Threshold LED
These LED's will show you the state of the input signal in relation to the threshold level. If the input signal
falls below the set threshold level the left "-" LED will light up. This means that no signal is being compressed.
If the input signal rises above the set threshold level, this signal will be compressed and the SKC level will be
shown by the middle "0" LED.
7. Ratio Control
The ratio between the input and output level of audio signals exceeding the set threshold level is determined by
this control. This control is manually adjustable from 1:1 to :1.
8. Attack Control
This control determines how fast the compressor is to respond to audio signals that will exceed the set threshold.
It can be manually adjusted from 1 to 150 ms.
9. Release Control
This control determines how fast is the compressor to return to unity gain when the audio signal falls below the
set threshold level. It can be manually adjusted from 0.05 to 5 seconds.
10.Auto Switch
Who needs attack and release control? Activate this switch and these controls will be deactivated. Attack and
release controls will be automatically set by the unit depending on the program material.
Pic. 3 Controls of the Compressor ection S
5
6
7 8 9 10
12
13 14
15
16 17
18 19
11
2. Threshold Control
This control adjusts the threshold level for the Expander / Gate Section in the range of Off to +15dBu. Signals
below this level cause expansion.
3. Ratio Control
This control determines the expansion ratio when the signal drops below the threshold level. The expansion
ratio can be set from 1:1.2 to 1:8 (Low ratio for Expander application or 1:8 for Gate application).
4. Threshold LED
The "+" Led lights up when an audio signal is below the set threshold. The "-" Led lights up in presence of an
expansion
3.2 Compressor Section
7
MANUAL
AUTO SC MONITOR
SC EXTERANL
dBu
-10
-30
+20
+10
-40
0
THRESHOLD
30 27 24 21 18 15 12 9 6 4 2
GAIN REDUCTION(dB)
4
10
1
2
N:1
RATIO THRESHOLD
dB/mSec
30
6 110
70 15
1 150
ATTACK
dB/Sec
0.5
3
1.5 0.3
5
0.1
0.05
RELEASE
SC FILTER I/O METER BYPASS
COMP dB
0
-10
OUTPUT GAIN
CH2
INPUT / OUTPUT LEVEL(dB)
-24 -18 -12 -6 0 6 12
SMART
+10
+20
1 18
COMPRESSOR