Dynamics Library Menu Page; Delay Menu - Behringer DDX3216 Operating Manual

(because loud mixes seem to sound better). Compression usually
involves thresholds well below the peak level of the music signal
(so that a substantial part of the signal is processed) and ratios
between 1:1 and 10:1. The attack and release times depend on
the program material processed.
Many compressors, including those in the DDX3216, can also
be used as limiters. Whereas a compressor limits the dynamic
range of the signal, a limiter makes sure that the signal does by
no means exceed a certain level, which is of particular importance
in radio broadcasting to ensure that the signal from one station
does not interfere with that from another. In live applications
limiters are used to prevent the power amps from going into
clipping, and in studios limiters avoid digital clipping. Limiters work
with thresholds that are close to the highest expected levels,
and very high ratios of 10:1 or even higher. The attack and
release times are usually relatively short.
Finally, we should discuss the parameters needed to control a
compressor or limiter:
The THRESHOLD is the level above which the signal is
compressed or limited. Above the threshold, the gain is
progressively reduced as the signal level increases. This routine
is like an automatic fader, which goes down, when the signal
level exceeds the threshold. The lower the threshold, the more
the signal is affected. Signals below the threshold, however,
remain unaffected. On the DDX3216 you can adjust a threshold
ranging from 0 dBFS (FS = digital full scale) to -60 dBFS.
The RATIO parameter determines how much the gain is
reduced for signals above the threshold. A ratio of 2:1 means
that with an input signal exceeding the threshold by 2 dB, the
corresponding output signal is boosted by only 1 dB, which
corresponds to a reduction of the dynamic range of 50% above
threshold. With a ratio of 10:1, a signal increase of 10 dB at the
input leads to a signal boost of only 1 dB at the output, which
results in a 90% reduction of the dynamic range. On your
DDX3216 you can adjust a compression ratio between 1:1 (no
compression) and 20:1 or "oo :1" (so-called hard limiting).
The ATTACK time determines how fast the compressor
responds to a signal surpassing the threshold. Low values make
the compressor reduce the gain almost instantly, once the signal
exceeds the threshold. With longer attack times the compressor
reacts more gradually. Low settings minimize overshoot, which
is particularly helpful for limiting. Extremely short attack times,
however, in particular on low frequencies, can produce
distortion. Longer attack times allow signal transients to pass,
but minimize the risk of distortion and hence preserve the
distinctive attack phase of certain instruments. On the DDX3216
the attack time can be adjusted from 0 to 200 ms.
The release time determines how fast the compressor restores
the original gain level, once the signal has dropped below threshold.
Fast release times cause the gain to be restored quickly; with
longer settings, the gain is restored more gradually. Short release
times minimize the duration of the gain reduction and are ideal for
peak limiting. In compressor mode (ratio of less than 10:1), fast
release times can lead to audible "pumping", because the
compressor is changing gains constantly and quickly. This effect
can be reduced by using longer release times. Finally, high values
of 3 to 5 s are often used for classical music to preserve the
dynamic relationships between various passages. On the DDX3216
the release time can be adjusted from 20 ms to 5 s.
The GAIN controller allows you to adjust the overall level of the
signal to be processed. Typically, the gain will be increased to
make up for the gain reduction in the compressor. In such a
case, the GAIN controller functions like a fader. The gain is
adjusted after the dynamics section, and can be adjusted from
0 dB to +24 dB.
The "knee" determines how the compressor reacts close to
the threshold. On the DDX3216 you can gradually adjust the
knee characteristic (one "hard" knee and five softer settings). In
hard-knee mode, the transition from "no gain reduction" to the
adjusted compression ratio is quite sudden; with a soft knee
setting, the transition is more gradual. This effect can be clearly
seen on the COMP(RESSOR) menu page: with a hard-knee setting
the graphic display of the compressor curve shows a sharp
angle at the threshold, with one of the five softer settings the
curve becomes gradually flat.
The key signal determines the amount of gain reduction. Normally,
the key signal is the same signal that is being processed (or the
mix signal of both channels in stereo-link mode). In certain
applications, however, it can be helpful to use another signal to
control the compressor. For example, you can "duck" a music
signal as soon as the signal delivered by an announcement
microphone exceeds a certain level. Another common use of the
key input is to use an equalized version of the signal to make the
compressor respond only to certain frequency ranges, for example
to eliminate "esses" ("de-essing"). On the DDX3216 you can set
the key input to SELF/SUM (stereo linked when channels are
paired) or assign it to any channel from the same fader bank. The
compressor on the MAIN output always works in stereo-link mode.
The DYNAMICS LIBRARY menu page offers a selection of
pre-programmed dynamics processing presets with descriptive
names. Of course, you can also name and save your own
presets.
To load a preset, turn one of the controllers below the preset
list, until the preset of your choice is selected, then press RECALL.
Loading a dynamics library preset will overwrite the A and B
settings in the GATE and COMP displays (gate and compressor).
The graphic display to the right of the preset list shows the
compressor response curve of each preset to give you a quick
overview of the parameter settings.
Use the DELAY switch in the switch block to display a menu
for the control of the channel delay and phase function. All of the
32 inputs feature a PHASE function, the first 16 inputs are
equipped with an additional delay unit.
Master controller 1 (PHASE) reverses the absolute polarity of
the signal (display "-" = phase is reversed by 180°).
The DELAY section (inputs 1-16) provides a pure time delay
for the alignment of signals in the time domain or to produce
delay effects.
Master controller 2 (FEEDBACK) routes the output signal from
the delay unit back to the input, which allows you to create an
"echo" effect. The higher the feedback value, the longer the
echo duration. Positive settings produce in-phase feedback, and
negative settings reversed-phase feedback. The DELAY
controller determines the delay duration (0 to 276 ms), which is
indicated in four different units of measurement (milliseconds
(MS), distance in meters (M), samples (SMP) and beats per minute
(BPM)).
+
3. DIGITAL CHANNEL PROCESSING

3.5.4 DYNAMICS LIBRARY menu page

Fig. 3.8: DYNAMICS LIBRARY menu page

3.6 DELAY menu

Fig. 3.9: DELAY menu
Please note that adjusting the delay time can
produce audible clicks, which is completely normal.
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