Behringer MDX1400 manual Introduction, Design Concept

AUTOCOM PRO MDX1400

1. INTRODUCTION

In purchasing the new AUTOCOM PRO Model MDX1400, you have acquired an extremely efficient and universal dynamics processor, which combines the most commonly used dynamic functions within a compact stereo unit: every channel has its own independent Compressor/Limiter, an Expander/Gate and a Dynamic Enhancer. The precision and flexibility of the functions are the main outstanding features of this high end unit.

Advanced BEHRINGER Technology

Compared to its predecessors, the AUTOCOM PRO offers several advanced features such as the extended LED meters, balanced inputs and outputs, a couple function for the two channels and the sidechain filter. Additionally, we have succeeded in refining the audio properties as well as the circuit topology.

For the first time, the AUTOCOM PRO MDX1400 uses SMD technology (Surface Mounted Device). These sub-miniature components known from aerospace technology allow for an extreme packing density, plus improve the unit’s reliability. Additionally, the unit is manufactured under ISO9000 certified management system.

1.1 The Design Concept

The philosophy behind BEHRINGER products guarantees a no-compromise circuit design and employs the best choice of components. The operational amplifiers NJM4580 which are used in the AUTOCOM PRO, are exceptional. They boast extreme linearity and very low distortion characteristics. The most important aspect of the AUTOCOM PRO design is a radical VCA implementation which results in outstanding technical specification and excellent performance. To complement this design the choice of components includes high precision resistors and capacitors, detent potentiometers and several other stringently selected elements.

Despite the extremely complex internal circuitry, the unit has a control surface which is clearly laid out and easy to understand. The internal design of the unit, together with its external sidechain path, gives the user all the creative flexibility when processing sound.

IKA (Interactive Knee Adaptation) Compressor

Our proven IKA (Interactive Knee Adaptation) circuit successfully combines the concept of a “hard knee” compressor with the characteristics of a “soft knee” approach. This program-dependent regulation scheme forms the prerequisite both for “inaudible” and musical program compression and for creative and highly effective dynamics processing.

The chosen value for the compression-ratio is being reached after the signal’s level is higher then 10 dB above the treshold point. This stands for an extremely smooth impact of the compression. Thereby a convincingly dense audiomaterial can be achieved: Even at extreme levels of compression or while processing critical audiodata (e. g. classical music), your material stays musical, transparent and free from breathing or pump- like effects in a wide range. With its IKA circuit the AUTOCOM PRO is capable of delivering outstanding musical results both in studio and live PA applications.

Additionally, the AUTOCOM PRO’s sidechain filter allows for limiting the influence low-frequency signal portions usually have on the control logic, so that the compression ratio is mainly determined by those frequencies that are essential to the loudness perceived by the listener – the midrange frequencies.

IRC (Interactive Ratio Control) Expander

A basic problem in the use of a compressor is the fact that the noise floor is highly amplified during quiet sections or when there are music pauses. This effect is exaggerated when the compression ratio is inappropriate. In order to eliminate this problem, one would normally use an additional expander or gate. The noise is then simply faded out in the quiet sections. However, simple expanders, even when they are used correctly, drastically cut signals below the preset threshold. This effect becomes more noticeable during the transition from signal to noise floor. This can mean, that the start or end of words can be cut on a vocal track.

A newly developed IRC (Interactive Ratio Control) Expander has been integrated into the AUTOCOM PRO the ratio of which, is automatically adjusted, depending on the program material. The result is an expander which is less critical of adjustment and which is more tolerant in the presence of those signals which appear slightly above the noise floor. Because of its new IRC circuit design, the BEHRINGER AUTOCOM PROs Expander/

6 1. INTRODUCTION