Junger Audio b42 - Dynamics Processor - Manual (Page 11)

2. FUNCTION DESCRIPTION
operation manual b40, chapter 2 -Function description- page 2-5
Independent of the compression ratio , the gain of the compressor
(range) can be limited (maximum 1 dB to 15dB), so that there should
be no inadmissible increase of background noises during signal
pauses (e.g. live atmos, air-conditioning, hum and noise).
The static characteristics of the b42 usually refers to a digital output
level of 0 dBFS (dB Full Scale). This is useful for most applications of
the dynamics processor as the on-following digital recording system is
supposed to be balanced down to the final bit.
For applications using headroom the output level of can be adjusted
within 0 ... -20 dBFS in steps of 0.1 dB. The limiter threshold
determines the maximum output level.
The static characteristics fo limiter (solid) and compressor (dotted) at a
limiter threshold of -12 dBFS are illustrated in fig. 5
.
audio processing of
compressor is related
to limiter threshold level
-50
-40
-30
-20
-10
[dBFS] -10 -20 -30 -40 -50 -60
output
input
limiter
threshold
0...-20dBFS
max. output
level
For the dynamics functions a signal delay of approx. 2 ms is built in.
This delay makes it possible to arrange the algorithm of the limiter in
such a way that the control mechanism is activated before maximum
level is reached (look ahead limiter). Within the rise time of the signal
the peak level is recognised and the maximum is calculated in such a
way that full scale level is reached precisely without causing clipping.
For some of the control parameter it is possible to define a limited
range of time constant values which is allowed for the adaptive
dynamic range algorithms. Inside this range the time constants can be
varied by the adaptive processing. Setting the range of time constant
values may be sometimes useful, to get the best signal processing
performance regarding specific programme material.
Parameter related to the transient response of the control circuit are
important for distortionfree processing. These time constants are
allways adaptive controlled without remarkable limitation of parameter
range. This is caused by the presence of transient pulses in allmost
2.3.5
LIMITER
fig. 5:
basic function:
limiter
2.3.6
PROGRAM