Dynamics Processing; Gate Menu Page; Comp(Ressor) Menu Page; Compressor Parameters - Behringer DDX3216 Operating Manual

The low-cut filter has only one frequency parameter, which
controls the frequency at which the signal is cut by 3 dB (cutoff
frequency). All frequencies below that value are attenuated
with a slope of 12 dB per octave. So, when you select a frequency
of 100 Hz, it will be cut by 3 dB; at 50 Hz it is 15 dB, and as much
as 27 dB at 25 Hz.
The low-shelf filter, too, is effective on all frequencies below
the selected cutoff frequency, however, here you can also
adjust the filter GAIN. The cutoff frequency is the frequency at
which the filter attenuates or emphasizes the signal by 3 dB.
Frequencies below that value are gradually cut or boosted, until
the maximum filter attenuation/boost is reached, which depends
on the GAIN setting. Normally, it corresponds to a range of one
octave above or below the selected cutoff frequency.
The top band of the EQ is also equipped with high-cut or high-
shelf filters, which function like the cut and shelf filters in the low
section, with the exception that they process the range above
the selected cutoff frequency.

3.5 Dynamics processing

Each of the 32 input channels is equipped with a full-featured
digital dynamics processor, which also includes compressor/
limiter and gate functions. Similar to the EQ section, you can
compare two settings (A and B) on the COMP(PRESSOR) and
GATE pages, and use a dynamics library that includes a wide
variety of pre-programmed settings with descriptive names. Of
course, you can also save and load your own presets.

3.5.1 GATE menu page

Press the GATE switch in the CHANNEL PROCESSING section
of the switch block to display the GATE menu page for the
selected channel. A gate allows you to automatically reduce the
level of unwanted signals or even eliminate them completely,
using roughly the same parameters as those found on a
compressor. However, a gate works below the threshold and
has the compression ratio replaced by a RANGE parameter which
provides a fixed gain reduction.
Fig. 3.6: GATE menu page
On the GATE menu page, master controller 1 adjusts the key
signal, which determines the amount of gain reduction. More
information on the key signal can be found in chapter 3.5.2

"COMP(RESSOR) menu page".

Master controller 2 controls both the ATTACK time and the gate
THRESHOLD. Turn this controller to edit the values of the selected
controls (surrounded by a dotted line), or press it to switch to
another parameter. Master controller 3 controls the RELEASE time
and gain reduction (RANGE), while master controller 4 allows you
to define the HOLD time. Master controller 5 performs the A/B
function, and master controller 6 activates the gate.
The HOLD time is the length of time which the gate stays
"open" after the signal has dropped below threshold. The shorter
this time, the faster the gate "closes", but this may cut off the
decay phase of the signal or cause the gate to open and close all
the time. The hold time can be adjusted from 10 to 1,000 ms.
The ATTACK time is the time which the gate needs to "open"
completely, once the signal has exceeded threshold. The shorter
this time, the faster the gate opens, but this may cause clicks.
Longer times produce no clicks, but may cut off part of the
signal's attack phase. The attack time can be adjusted from 0 to
200 ms.
The RELEASE time is the time which the gate needs to "close"
completely, once the signal has dropped below threshold, and
20
after the hold time has passed. Short release times make the
gate close faster, but can affect the signal's decay phase. Long
release times make the gate close less abruptly. The release
time can be adjusted from 20 ms to 5 s.
The RANGE is the amount of gain reduction applied when the
gate has "closed". Here, the setting range is from 0 (no gain
reduction) to -60 dB. "-oo" means maximum gain reduction, i. e.
the audio signal is faded out completely below threshold.
The graphic displays on the right are described in chapter
3.5.2 "COMP(RESSOR) menu page".
The compressor works like a conventional analog compressor,
providing gain reduction above the threshold, but offers the
flexibility and performance of a digital dynamics processor.
Press the COMP(RESSOR) switch in the CHANNEL PROCESSING
section of the switch block to display the COMP(RESSOR) menu
page for the selected channel. To scroll through the available
menu pages, simply press the COMP(RESSOR) switch repeatedly.
On the COMP(RESSOR) menu page, master controller 1 controls
the key signal, which determines the amount of gain reduction
applied. The key signal is used both for the compressor and the
gate. The default is SELF/SUM, i. e. the input signal is also the
signal used to determine the gain reduction. When channels are
paired (stereo), the dynamics sections of both channels are
linked automatically, and their mix signal serves as the key signal
for both of them. This is to guarantee an identical gain reduction
in both channels and thus a stable stereo image (see chapter

3.5.3 "Compressor parameters").

Master controller 2 adjusts the THRESHOLD and the ATTACK
time. Turn this controller to edit the values of the selected controls
(surrounded by a dotted line), or press it to switch to another
parameter. Similarly, master controller 3 governs the parameters
compression RATIO and RELEASE time. Master controller 4
determines the makeup gain (GAIN) as well as the compression
characteristic curve at the threshold (KNEE). Finally, master
controller 5 performs the A/B function (see above), and master
controller 6 switches the compressor IN or OUT.
The graphic on the right side of the display shows the curves
and meters for the entire dynamics processor, including the
gate. Displayed are the compressor characteristic curve based
on the adjusted parameters threshold, ratio, knee and gain as
well as the gate parameters threshold and range. In particular,
the GAIN controller can be adjusted conveniently with the graphic
display, and also the position of the IN/OUT switches is shown
clearly: when the compressor and gate are off, the display shows
a 45° straight line (indicating no processing).
The far right part of the display shows two level meters for the
input level (I = Input) and the gain reduction applied (GR = Gain
Reduction). The GR value is the sum of the compressor and gate
gain reduction.
Compressors are used to limit the dynamic range of a signal
for technical or musical reasons. For example, you can compress
a symphony orchestra recording to make background music—
allowing the soft passages to be heard and keeping the loud
passages from overwhelming all conversation. Vocal and
instrumental tracks are often compressed to give them more
"punch" and presence in the overall mix. Thus, compressors
reduce the need to "ride the faders" during the mixdown. Complete
mixes are often compressed to increase their apparent loudness
3. DIGITAL CHANNEL PROCESSING
3.5.2 COMP(RESSOR) menu page
Fig. 3.7: COMP(RESSOR) menu page
3.5.3 Compressor parameters