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MULTIGATE PRO XR4400 User Manual
output
input
gain 0 dB
IRC curve
expander. 1:8
noise gate, 1:∞
threshold
Fig. 6.3: IRC characteristic curve
The result is an expansion process that is less difficult to adjust and more tolerant
towards wanted signals whose levels are only slightly above the level of the
background noise.
5.2.6 RATIO function
The ratio of the input-level-change vs. output-level-change after the onset of the
control process, i.e. after the signal has dropped below the threshold, is called
expansion ratio and can be set with the RATIO control. RATIO settings from 1:1.2
through 1:4 give you smooth and exactly dosed downward expansion.
The RATIO scale printed on the front panel indicates the expansion ratio in
decibels, i.e. it shows you the decibels by which the output signal is cut for each
reduction by one dB of the input signal.
With a 1:1 ratio the output signal level is the same as the input signal level,
i.e. there is no signal change. A ratio of 1:2 means that the output signal is
reduced by 2 dB when the input signal drops below the threshold by 1 dB.
Accordingly, with a ratio of 1:4, the output signal is cut in level by 4 dB when the
input signal is 1 dB below the threshold.
5.3 FLEXLINK function
The four channels of the MULTIGATE PRO can be operated both independently
of each other and in couple mode. In particular, when you record a choir it will
be useful to couple the individual microphone channels. For example, when all
microphones are controlled by one singer, all vocals start and stop precisely
at the same point of time. Also when synchronizing several instruments,
inaccurate entries of individual musicians can be avoided.
To expand phase-coherent stereo signals (i.e. signals having the same phase),
it is imperative that the control processes be triggered simultaneously in both
channels. Due to the differences in perceived loudness between the left and right
channels, unwanted shifts with reference to the stereo basis would be produced.
The innovative FlexLink function implemented in the MULTIGATE PRO allows for
a variety of couple options. For example, when you press the COUPLE switch of
channel 3, this channel is automatically configured as a “slave” channel, while its
neighbor—channel 2—becomes the “master” now controlling both channels in
all their parameters.
Activating the COUPLE switch automatically disables all controls and switches
of channel 3 (except for the MONITOR switch). Now, the controls of channel 2
take over full control of channel 3. Similar to a stereo fader, both channels work
in sync. To control channels 2 and 3 from channel 1, simply press the COUPLE
switches of channel 2 and 3.
5.4 The SIDECHAIN filter
Each channel has a parametric filter whose frequency and quality (bandwidth)
can be set precisely. This tunable filter allows you to select and fade out
specific frequencies that would otherwise lead to unwanted triggering of the
expander circuit.
5.4.1 The MONITOR function
This switch links the sidechain control signal with the audio output, while muting
the audio input signal, so that you can pre-monitor the filter output and tune the
parametric filter.
◊
Please note that the channel’s entire processing functions will be
disabled when you press the MONITOR switch.
6. Applications
This chapter describes a few typical applications of the BEHRINGER MULTIGATE
PRO. Starting from the basic setting shown below you can find solutions to
most dynamics-based problems. Please take your time to study the following
application examples thoroughly, so as to be able to fully exploit the variety of
features your MULTIGATE PRO offers.
Basically, the BEHRINGER MULTIGATE PRO can be used in three areas
of application:
1. Eliminating interference noise and suppressing crosstalk in multi-channel or
multi-microphone configurations.
2. Expanding the dynamic range of compressed program material,
refreshing sampled sounds and creating special effects and sounds.
3. Using the MULTIGATE PRO as a de-esser and to specifically eliminate
interference noise from recordings as well as to reduce the risk of feedback
in live situations.
6.1 Basic setting
Understandably, there is no standard setting that suits all kinds of applications.
Rather, the controls and switches must be set specifically for the application
on hand. However, by studying the following practice-oriented descriptions
of typical applications you will soon develop a feel for how the various
functions work:
6.1.1 The gate function
“Gating” is a so-called “high ratio” expander function and represents the
simplest function of the BEHRINGER MULTIGATE PRO. When the expander is
operated with maximum gain reduction (RANGE control fully to the left), it works
in “hard gating” mode. The gate function is used to automatically mute single
channels in multitrack mixdowns, stage microphones currently not in use and to
suppress background noise and crosstalk in multi-track recordings. In particular,
when processing percussive instrument the use of the “hard gating” function
is recommended.
A few examples show you how to do it:
Electric signals from percussion instruments have a very short rise time. The time
between single hits on the instruments is normally filled up with noise produced
by adjacent instruments or room reverb, which makes it difficult or even
impossible to separate microphones acoustically. This unwanted crosstalk effect
can be accurately eliminated with the MULTIGATE PRO.
