User`s manual

11
5. INSTALLATION AND CONNECTION
5.1 Mains Connection
5.2 Audio connection
4.2.8 Gain Reduction eterM
Chart.6: The effect of a compressor can be expressed as the amount
of gain reduction that is taking place for any given input
4.3 Limiter Section
Chart.7: SGC characteristic of the limiter section
Peak Limiting
6ms 15ms
Level
Program Limiting
Input
Release
Output
approx. 1 s
Threshold
t/ms
30
20
10
This consists of 12 LED on the front of the ACL2. Through this Led meter you can visualise the amount of
gain reduction at any given time.
How fast is the compressor to react to a signal which is above the threshold point? This is determined by the
attack time. A longer attack time is advisable to process low frequencies while shorter attack time is preferable
for high frequencies. In this way you will avoid undesired dynamic distortion. But what about if you are mixing a
program with a wide range of frequencies? In this case you should choose a setting that would benefit the low
frequency better. Well, life is not that easy for conventional compressor/limiters. Ok you handle an audio signal
made by a wide range of frequencies and you have chosen a longer attack time. But, if using your ACL2 as a lim-
iter the fast high frequencies will pass through untouched because the attack time is too slow and such transients
could cause distortion when the unit is connected to broadcast devices or taper recorders.
The solution in ACL2 is represented by our Smart Gain Control (SGC) limiter circuit. The curve in bold is the out-
put signal and the dashed curve above it is the input signal. The area in between the two is the amount of gain
reduction. The unit will activate the limiter when the signal exceeds the threshold for more than 15 microseconds.
Then 1 second after that the signal is below threshold again, reduction goes back to 0dB and in this case input
and output signals are again identical.
ACL2 is provided with dual voltage plug. You must check the power supply Voltage available in your country
before connecting the power cord in the wall outlet.
The ACL2 Compressor/Limiter/Gate is equipped with balanced XLR connectors as well as 1/4" phone jack and
can be connected with other units in different ways to support a vast range of applications without experiencing a
signal loss.
GAIN REDUCTION
dBu
(Hard Knee)
Input/dBu
0
-5
-10
-10
-5
0
+5
+10
1:1
2:1
4:1
10:1