Behringer MDX4400 manual Dynamic range capabilities of various devices

MULTICOM PRO MDX4400

P/dB
140
120
100
80	MicrophoneAmplifier
60		PowerAmplifier	TapeRecorder
40				Radio	Cassette Recorder
Ear

Fig. 1.1: The dynamic range capabilities of various devices

It is therefore useful to keep the operating level as high as possible without risking signal distortion in order to achieve optimum transmission quality.

It is possible to further improve the transmission quality by constantly monitoring the program material with the aid of a volume fader, which manually levels the material. During low passages the gain is increased, during loud passages the gain is reduced. Of course it is fairly obvious that this kind of manual control is rather restrictive; it is difficult to detect signal peaks and it is almost impossible to level them out. Manual control is simply not fast enough to be satisfactory.

P/dB

Clipping

+20

Headroom

0

Operating level

-20

-40

Effective SNR

-60

-80

Noise floor

t

Fig. 1.2: The interactive relationship between the operating level and the headroom

The need therefore arises for a fast acting automatic gain control system which will constantly monitor the signals and which will always adjust the gain to maximize the signal-to-noise ratio without incurring signal distortion. This device is called a compressor or limiter. This system is a part of the BEHRINGER MULTICOM PRO.

8 1. INTRODUCTION