dbx Pro QUANTUM user manual Broadband Compression

Section 4 Detailed Parameters

QUANTUM

4.2 Broadband Compression

The broadband compressor can be used in both stereo or dual mono configurations. Within the broadband compressor menu on the QUANTUM the following parameters are user adjustable on all setups.

Compressor On/Off

Turns compressor module on and off.

OverEasy® 1-10

The point when the QUANTUM (or any compressor) starts to compress is the "knee." When the QUANTUM starts to reduce the level of a signal abruptly right as it passes over the threshold this is called "hard knee" compression. OverEasy® (soft knee as it is sometimes called) is when the volume of the sound is compressed gradually. OverEasy® compression starts to compress before the level of the signal reaches the threshold and reaches full compression after the level has gone above the threshold. This OverEasy® compression, by its very nature sounds much smoother and more natural and will be used for most applications. When it is gentle (natural sounding or light) compression that you are looking for, the QUANTUM has what we call VariKnee™. VariKnee™ gives you ten levels of OverEasy® compression to choose from (1 being almost hard knee and 10 being the most OverEasy®). This lets you choose the exact knee that is needed for the dynamic effect you are looking for.

see Fig. 4.1

Auto On/Off

When Auto Mode is on, the QUANTUM automatically sets the Attack, Hold, and Release times for the signal. The auto mode constantly adjusts these parameters in real time for optimum per- formance from the unit. You will find that for most applications, not only is using the auto mode faster and easier but by letting the unit constantly tweak these parameters for you will result in a better end result (try and hit a snare exactly the same for three minutes).

Threshold -60 to 0 dB

Threshold is the signal level at which the QUANTUM starts to compress the signal. If the level is set to -10 dBFS, than any signal larger than -10 dBFS is compressed while any signal that has a level that is lower than -10dBFS is left at the same signal level. Light compression is where only the loudest parts of the signal go over the threshold. Very heavy compression can be achieved by setting the threshold low enough that almost the entire signal content is over the threshold. For most signals the most natural compression is achieved when most of the signal content remains just below the threshold and only the peaks cross the threshold.

Ratio 0.75 to Inf:1

Ratio is the amount the QUANTUM reduces the signal level of the sound that is above the threshold. A 2:1 ratio means that if the incoming signal is 2dB over the threshold the QUAN- TUM will compress the signal, and outputs a signal that only goes 1dB over the threshold. For light compression choose a lower ratio, while for heavy compression a higher ratio is used. By setting the ratio at less than 1:1, the signal will be expanded. The QUANTUM will actually out- put a signal larger then the input. At a ratio of 0.75:1, if a signal goes over the threshold by 0.75dB, the unit will output a signal that is 1 dB over the threshold.

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32 QUANTUM User Manual