Home
Главная
Behringer
Звуковой компрессор
XR4400
Руководство по эксплуатации Страница: 11

Behringer XR4400 [11/14] Proper positioning of microphones

11 MULTIGATE PRO XR4400 User Manual

Adjust all controls and switches to the following basic settings:

Control elements Position

MONITOR switch OUT

SC FILTER switch OUT

THRESHOLD switch fully clockwise

HOLD control center position

RELEASE control center position

MODE switch GATE

RANGE/RATIO control fully counter-clockwise

Tab. 6.1: Initial settings of the MULTIGATE PRO

THRESHOLD control

Now turn the THRESHOLD control counter-clockwise until the lowest signal

delivered by the instrument you wish to record triggers the expander and is

reproduced without any sound deterioration. The “+” LED lights up as soon as

the expander is triggered. When everything’s set up properly, you will hear the

instrument clearly “stand out” against the overall sound image.

HOLD control (available in GATE mode only)

The program material (e.g. speech/vocal recordings) often contains many and

sometimes very short signal pauses, which could switch the gate o and back on

over and again. The hold function prevents this annoying “utter” eect known

from conventional designs, simply by delaying the starting point of the release

process. Thus, the gate remains on during short signal pauses. When the adjusted

hold time has expired, the gate closes the audio channel depending on how the

release function has been set.

◊ Please note that this control can be used in gate mode only!

RELEASE control (available in GATE mode only)

Many percussion instruments have long decay times (e.g. cymbals). As the release

time can be adjusted on the MULTIGATE PRO, the device allows you to follow the

decay curve of the instrument so that its overall sound character will be retained.

In this way, you can avoid that short release times aect the natural decay phase

of the instrument or its corresponding reverb ambiance.

Slowly decaying or heavily reverberated signals are best processed with long

release times. You will note that with most drum sounds a short release time

should be used for the sake of acoustic separation, while longer release times are

usually better for cymbals and tom-toms.

Once all control elements have been set properly, your percussion sounds will be

“dry”, “powerful” and acoustically well-dened.

◊ Please note that this control can be used in gate mode only!

RANGE control

The RANGE control determines the amount of maximum attenuation of the

audio signal. When you process instruments with long decay times, it will

be helpful to set the RANGE control to mid-travel position, so that the signal

will not be suppressed completely. Although the MULTIGATE PRO allows for a

maximum gain reduction of 80 dB, it is usually not useful to reduce the signal

level by this maximum amount. In particular, with highly noise-aected signals

we recommend that you use a signal attenuation of not more than 10 to 20 dB,

sothat the onset of the gate function will not become too obvious.

6.1.2 The expander function

In contrast to the gate function, the expander triggers a continuous attenuation

of the signal, as soon as it has dropped below the threshold.

RATIO control

With the MODE switch in, the MULTIGATE PRO works as an interactive expander.

The RATIO control determines the expansion curve. For example, when a piece

of music was highly compressed during the recording session, the lost dynamics

can be restored through complementary expansion. With a bit of feeling you

can set the following controls by ear so that the original dynamics (prior to the

compression process) will be restored.

We recommend that you set the RATIO control to about 1:1.2 through 1:2 to allow

for a “smooth” expansion curve, and that you adjust the THRESHOLD control so

that the entire dynamic range of the music piece will be below the threshold

point. Now set the THRESHOLD control so that only the loudest passages of the

program material surpass the threshold point (“-” LED ashes). In the same way,

you can articially expand the dynamic range of any instrument. Inparticular,

when processing sampled sounds, expansion can produce nice results,

becausesamplers usually have a highly limited dynamic range. When processing

percussion sounds (e.g. snare drum) you can use downward expansion to create

interesting eects, for example, by setting the threshold to about mid-position,

so that only the “lower” part of the dynamics will be processed: the signal decays

unchanged until the adjusted threshold is reached, and any subsequent signal

portions are faded out with increasing attenuation.

6.2 Proper positioning of microphones

The main task of an expander is to separate unwanted background noise from the

actual signal and to eliminate this noise “inaudibly”. Understandably, there must

be a minimum dierence in the levels of wanted signal and interference signal,

so as to be able to dene a threshold point for the expander.

However, the optimum operation of an expander depends on the proper choice

and positioning of the microphones:

Be extremely careful when instruments with high-frequency portions are played

to the sides or back of a microphone with a cardioid polar pattern. Most room

microphones suer from a deterioration of their directivity when picking up

high frequencies. For example, with a sensitivity dierence of not more than

2-3dB around 5-10 kHz between the main and lateral axes, cymbals can produce

enormous crosstalk in tom-tom microphones, or the hi-hats can mask the sound

of the snare drum.

You should make optimum use of the specic directivity of a microphone to

acoustically separate other instruments as perfectly as possible. Do as best as

you can to separate the sound sources acoustically simply by positioning the

microphones correctly.

Yet, in some applications even perfectly positioned microphones might

not produce satisfying results. With its side-chain function the BEHRINGER

MULTIGATE PRO gives you the option of frequency-selective expansion and thus

another aid to ensure perfect acoustic separation of the sound sources.

Behringer XR4400 [11/14] Proper positioning of microphones

Содержание

Похожие устройства