Nady Systems dig comp 16 Installation and Connection, Audio Connections and Power Up, Analog

DigiComp16booklet 1/23/03 10:33 AM Page 16

Installation and Connection

Audio Connections and Power Up

The connections between the DigiComp 16 and other audio devices have to be made using high-quality cables to insure optimum performance of this unit. It is best to use low capacitance shielded cables with a flexible internal conductor. Connect the cables to the unit properly by observing the following precautions:

•Do not bundle audio cables with AC power cords.

•Do not place audio cables and DigiComp 16 near sources of electromagnetic interference such as transformers, monitors, computers, etc.

•Always unplug cables by firmly grasping the body of the plug and pulling directly outward.

•Do not place cables where they can be stepped on.

•Avoid twisting a cable or having it make sharp, right angle turns. Before powering up the DigiComp 16, check that all connections have been made correctly.

•Turn down volume controls of the amplifier or mixer. Insert the Power plug into the POWER input on the rear panel of the DigiComp 16 and plug the power adapter into an AC outlet. Turn on the power of the amplifier/mixer and adjust the volume.

Analog

a. Input Jack Wiring

The DigiComp 16’s LEFT INPUT (12) jack is also the mono input for the unit. If you only connect a single mono cable to the LEFT INPUT (12) jack, it will also be routed automatically to the RIGHT INPUT (13). However, if you are using stereo input signals and also connecting a cable to the RIGHT INPUT (13) jack, the automatic routing will be avoided and the left input cable will feed only the LEFT INPUT (12), and the right input cable will feed only the RIGHT INPUT (13).

b. Level Setting

Proper setting of the input and output levels is crucial in order to achieve the maximum signal-to-noise ratio. It is

usually best to set both input

and output level controls at 3/4 or 75% of maximum. This will decrease the possibility of

overload distortion and keep

the amount of background noise to a minimum. If the Signal LED (4) on the DigiComp 16 lights up, signaling a process saturation, turn down the INPUT LEVEL (1) or decrease the volume of the source (instrument, mixer send, etc.). If the unit level is causing the mixer or amp to distort, turn the OUTPUT LEVEL (2) down.

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Dynamic Compression Process

As the name implies, compression reduces the dynamic range of a signal. It is used extensively in audio recording, production work, noise reduction, and live performance applications, and needs to be used with care. A compressor is basically a variable gain device wherein the amount of gain used depends on the level of the input. In this case, the gain will be reduced when the signal level is high, making louder passages softer

and reducing the dynamic range.

A compressor’s input/output relationship can be illustrated by a simple graph:

The horizontal axis corresponds to the input signal level, and the vertical axis is the output level (both measured in decibels). A line at 45 degrees corresponds to a gain of one — any input level is mapped to exactly the same output level. The compressor changes the slope of that line (makes it more horizontal) above some value called the threshold (which is most often adjustable). The height of the line defines the dynamic range of the output, and the slope of the line is the same as the compressor's gain.

Stereo 2 Bands Compressor

The DigiComp 16’s Stereo 2-bands dynamic process algorithm is based on a "multiband" process concept, splitting the full band of the input signals into 2 "sub-bands" — the low frequencies band and the mid/high frequencies band — in order to differentiate the dynamic processes operating on the low frequencies (with higher energy content) and the mid/high frequencies (with lower energy content).

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