Behringer Multigate Pro XR4400 オーナーマニュアル

MULTIGATE PRO XR4400 User Manual

With the BEHRINGER MULTIGATE PRO you purchased a dynamics processor of the 

high-end class designed to meet highest requirements: professional recording, 

broadcast and television studios, CD and digital production facilities, 

etc. Its complete range of features and innovative circuit topology make 

the MULTIGATE PRO an all-purpose device for reducing noise in audio 

recordings, for automatically muting stage mics, expanding the dynamic 

range of compressed recordings, improving the signal-to-noise ratio of noisy 

communications systems and for producing special effects, etc.

Future-oriented BEHRINGER technology 
Our MULTIGATE range of devices has been a hit ever since we introduced our first 

model several years ago. This expander/gate is based on many years of experience 

and findings in psychoacoustics and is used throughout the world in renowned 

studios, sound reinforcement systems as well as in broadcast and television studios. 
It was a real challenge to improve the well-known MULTIGATE even further, 

and we are proud of our success. Compared to its predecessor models, 

the MULTIGATE PRO not only has additional features, but also comes with 

dramatically improved functionalities. For example, it now has a parametric filter 

enabling you to accurately set the trigger frequencies, while the FlexLink system 

allows for great flexibility when linking the device’s individual channels in a 

master/slave configuration.
Basically, quadruple gates are not a new invention. However, packing four simple 

noise gates into one enclosures usually means a compromise in terms of ease 

of operation and functionality. Too many control elements make such a device 

impossible to handle, and if you sacrifice crucial functions for the sake of easy 

operation, the range of useful applications is restricted considerably.
The BEHRINGER MULTIGATE PRO is a quadruple expander/gate with a maximum 

of functionalities and can still be operated conveniently. Interactive functions 

make it easy and efficient to specifically process any kind of program material, 

while the need for “adjustment work” has been reduced drastically. Each of 

the MULTIGATE PRO’s four sections comprises an ultra-fast gate, a program-

dependent expander, a filter section and high-precision meters indicating both 

threshold point and gain reduction.

The IAC circuit (Interactive Attack Control)
One of the MULTIGATE PRO’s most outstanding features is the program-dependent 

control of attack times. The new IAC circuit (Interactive Attack Control) analyzes 

the program material to calculate the attack time by way of interaction, so that the 

hold/release process is triggered automatically depending on the program, which is 

why the MULTIGATE PRO does not need a dedicated attack control.

Switchable gate/expander function 
Another highlight of the MULTIGATE PRO is the switchable operating mode of 

gate and expander. With the MODE function off, the MULTIGATE PRO works in 

gate mode using an extremely fast attack time to gate all kinds of drum and 

synthesizer sounds, without cutting their percussive edge.
In expander mode the device analyzes the shape and dynamic contents of 

the input signal to calculate the control time parameters. It thus works as an 

interactive expander that adapts automatically to the program signal. The result: 

guitar sounds, vocals and complex mix signals can be “cleaned” without audible 

clicks, breathing or other detrimental effects. Additionally, you can freely expand 

any type of program material in its dynamic range.

Side-chain filter section
When several microphones are used, for example to pick up a drum set, crosstalk 

between microphones can lead to unwanted triggering of the gate. The built-in 

parametric sidechain filter of the MULTIGATE PRO allows the user to accurately 

select the frequencies causing the trouble, so that the device responds to 

these frequencies only. The monitor function can be used to pre-monitor the 

filter, making it easier to adapt the circuitry to the acoustic properties of the 

program material.

FlexLink system
An innovative couple function gives you great flexibility to synchronize the 

expander/gate sections in a master/slave configuration.

By employing current modern analog technology it is possible to manufacture 

audio equipment with a dynamic range of up to 130 dB. In contrast to analog 

techniques, the dynamic range of digital equipment is approximately 25 dB 

less. With conventional record and tape recorder technology, as well as 

broadcasting, this value is further reduced. Generally, dynamic restrictions are 

due to noisy storage in transmission media and also the maximum headroom of 

these systems.

1.1.1  Noise as a physical phenomenon
All electrical components produce a certain level of inherent noise. 

Current flowing through a conductor leads to uncontrolled random electron 

movements. For statistical reasons, this produces frequencies within the 

whole audio spectrum. If these currents are highly amplified, the result will be 

perceived as noise. Since all frequencies are equally affected, we term this white 

noise. It is fairly obvious that electronics cannot function without components. 

Even if special low-noise components are used, a certain degree of basic noise 

cannot be avoided.
This effect is similar when replaying a tape. The non-directional magnetic 

particles passing the replay head can also cause uncontrolled currents and 

voltages. The resulting sound of the various frequencies is heard as noise. 

Even the best possible tape biasing can “only” provide signal-to-noise ratios of 

about 70 dB, which is not acceptable today since the demands of listeners have 

increased. Due to the laws of physics, improving the design of the magnetic 

carrier is impossible using conventional means.

1.1.2  What are audio dynamics?
A remarkable feature of the human ear is that it can detect the most wide 

ranging amplitude changes—from the slightest whisper to the deafening roar 

of a jet-plane. If one tried to record or reproduce this wide spectrum of sound 

with the help of amplifiers, cassette recorders, records or even digital recorders 

(CD, DAT etc.), one would immediately be restricted by the physical limitations of 

electronic and acoustic sound reproduction technology.
The usable dynamic range of electro-acoustic equipment is limited as much 

at the low end as at the high end. The thermal noise of the electrons in the 

components results in an audible basic noise floor and thus represents the 

bottom limit of the transmission range. The upper limit is determined by the 

levels of the internal operating voltages; if they are exceeded, audible signal 

distortion is the result. Although in theory, the usable dynamic range sits 

between these two limits, it is considerably smaller in practice, since a certain 

reserve must be maintained to avoid distortion of the audio signal if sudden level 

peaks occur. Technically speaking, we refer to this reserve as “headroom”—

usually this is about 10 - 20 dB. A reduction of the operating level would allow for 

greater headroom, i.e. the risk of signal distortion due to level peaks would be 

reduced. However, at the same time, the basic noise floor of the program material 

would be increased considerably.