Special applications – Behringer MDX2200 User Manual

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COMPOSER PRO MDX2200

Output

Input

Peak Limiting

Program Limiting

Release

Threshold

t/ms

Level

20 ms

5 ms

approx. 1 s

Fig. 4.3: IGC characteristic of the limiter section

The diagram illustrates the functioning of the IGC limiter. The solid graph represents the output signal, while the

dashed graph above shows the input signal response. The areas between the graphs represent the amount of

gain reduction (bright areas are clipping areas, i.e. signal peaks are radically cut off, dark areas show the

effect of the program limiter). The limiter is activated when the adjusted threshold is exceeded for more than 20

ms, so as to limit audible clipping to a very short moment. About 1 s after the signals has dropped below the

threshold again, the reduction is set to 0 dB, so that input and output signals are identical again (unity gain).

4.4.1 Initial settings for the peak limiter section

Tab. 4.3: Initial settings for the peak limiter section

The THRESHOLD control of the Peak Limiter sets the threshold level, so that subsequent units are protected

from overloading. If the LIM comes on regularly or is on constantly, the OUTPUT control of the Compressor

section must be turned down, as this control sets the level of the signal, which is routed to the Peak Limiter

section.
If this technique leads to an undesired drop in the overall level, it is recommended that you increase the

compression: either, reduce the threshold level, or increase the compression ratio with the RATIO control. The

OUTPUT control will compensate for a renewed drop in level.

5. SPECIAL APPLICATIONS

5.1 Using the COMPOSER PRO for recording and cassette duplication

In the recording and duplication field the goal should always be to achieve an optimum recording level onto the

recording media. Too low or too high recording levels lead to side effects such as noise, distortion etc. In

mastering and multitrack recording, as well as in duplication, one should always take care to utilize the full

dynamic range of the tape recorder, DAT recorder etc. Principally, it is possible to control the recording level by

riding faders, which means with low level signals, the gain is increased, whereas the amplitude of high level

signal is reduced. It is obvious that this method is insufficient because, especially in live recordings, the

expected signal levels cannot be anticipated correctly. Especially with multitrack recordings, which are run

under hectic circumstances, the signal level of all channels cannot be monitored and controlled at the same

time. Generally, with manual control, it is not possible to achieve satisfying recording results.
An automatic gain control system achieves better and more constant results. Use the COMPOSER PRO by

starting with the initial settings, and use its dynamic control functions in order to be able to drive an analogue,

as well as a digital recording, up to the limit of its maximum dynamic range while remaining noise- and

distortion-free.

5. SPECIAL APPLICATIONS