dbx Pro 162SL user manual OverEasy And Hard Knee, Using The Compression Control

OverEasy® And Hard Knee

In a typical hard-knee compressor, the threshold control sets a reference level above which input sig- nals will be attenuated in the manner defined by the setting of the Compression ratio control. Input sig- nals which fall below this level will pass through unprocessed. With OverEasy compression, signals begin to gradually activate the 162SL's gain change circuitry as they approach the threshold reference level and they do not get fully processed in the manner defined by the Compression control until they have passed somewhat above the threshold reference level. There is no distinct point at which pro- cessing begins, and the threshold setting corresponds to a point on the input/output transfer curve mid- way between the onset of processing and that point at which the transfer curve corresponds to the set- ting of the Compression control. The following diagrams also show how the 162SL's threshold indicator LEDs correlate with the compression curves.

OUTPUT LEVEL (dB)

1:1 Unity

+20

+15	2:1
+10	4:1
+5	20:1
0	:1
-5	Rotation Point Threshold

-10

-15

-15 -10 -5 0 +5 +10 +15 +20

INPUT LEVEL (dB)

OUTPUT LEVEL (dB)

+20

+15

+10

+5

0

-5

-10

-15

					1:1
					2:1
					4:1
					:1
				R	RED
				E
				B	Above Threshold
				M
				A
	R	E	EN	OVEREASY® RANGE
G

Below Threshold

-15 -10 -5 0 +5 +10 +15 +20

INPUT LEVEL (dB)

Hard knee compression	OverEasy® compression
threshold point.	threshold and LEDs.

Using The Compression Control

When an input signal is above the threshold reference level, the setting of this control determines the number of decibels by which the input signal must change in level to produce a 1dB increase in the sig- nal level at the output of the 162SL. A setting of 2:1 indicates an input:output ratio wherein a 2dB increase in input signal (above threshold) will produce a 1dB increase in output signal. A setting of ∞:1 indicates that an infinite increase in input level would be required to raise the output level by 1dB. In other words, the output level is constant when the input signal is above threshold. The 162SL's Compression control covers the entire range from 1:1 to ∞:1. The control curve of the compression potentiometer has been designed to provide total operator control, with scale expansion at the subtle lower ratios for easy, repeatable settings.

Behavior of the 162SL’s Compression control

		3		6
	2			10			1:1
	+20	1.5		20
(dB)	+15	1
							2:1
		COMPRESSION
	+10
LEVEL
							4:1
	+5						:1
OUTPUT
	0
	-5
				Threshold
	-10
	-15					-1:1
	-15	-10	-5	0	+5	+10 +15	+20

INPUT LEVEL (dB)

17