Behringer MDX4400 User Manual

Page 17

MULTICOM PRO MDX4400

5.2 Compressor Section

The task of a compressor is to reduce the dynamic range of program material and to control the overall level.

The extensive controls of the Compressor section, provide a great range of dynamic effects: from musical and

soft compression to limiting signal peaks, right up to extreme and effective compression of the overall

dynamics. For example, a low ratio and very low threshold setting can be used to achieve soft and musical

processing of the general dynamics of the program material.
Higher ratios, together with low threshold settings, create relatively constant volume (leveling) for instruments

and vocals. High threshold levels generally limit the overall level of a program. Ratios greater than 6:1 effectively

prevent the output level from significantly exceeding the threshold point (provided that the OUTPUT control is in

the 0 dB position).
Please note that the compression of the entire program material (achieved by low threshold settings) sounds

less natural with higher ratio settings. Ratio settings in the range of 4:1 and lower, effect the dynamics of the

program material less and are often used to compress the sound of a bass guitar, a snare drum or a vocal.

Sensitive and moderate settings are generally used in mixing and for leveling of program material in broadcast.

Threshold

Gain 0 dB

Input

Output

oo:1

Limiter

Ratio 2:1

Ratio 4:1

Hard Knee

IKA Curve

Fig. 5.1: IKA characteristic of the compressor section

The new IKA (Interactive Knee Adaptation) circuit prevents aggressive compression, created by high ratios,

from sounding too unnatural. This is achieved with an interactive control function, which begins above the

threshold level and introduces a Soft Knee curve characteristic in the range up to 10 dB above the threshold

point. Beyond this range, the signal is subjected to linear (Hard Knee) compression.

With the threshold control completely turned to the right, the threshold value is +20 dB. Since

such a value will not be reached in practice, you can use it to disable the compressor section

and work exclusively with the limiter circuits.

5. APPLICATIONS