Parameters; Threshold; Gain Reduction Meter; Ratio - E-Mu 1212m Owner's Manual

parameter to operate over an exceptionally large range of 0-60dB so that it can be
"steered" to the appropriate range of the input signal. The output Gain parameter also
operates - either manually or automatically - over the unusually large range of -60dB to
+60dB in order to renormalize the compressor's output for the next stage of the signal
path.
The wide dynamic range of the RFX Compressor aside, it's generally a good idea to
maintain the hottest signal levels possible without clipping at the input to any audio
processor.

Parameters

Threshold

Threshold sets the input signal level above which dynamic range compression takes
place. Everything above the threshold will be brought down in volume. The
compression threshold ranges from -0 to -60dB, relative to full scale (0dBFS) input.
Setting the Threshold to 0dB disables normal compression, since no signal can exceed
the maximum possible input level. A Threshold setting of 0dB is still useful, however,
when using soft-knee compression or gating, since these actions occur below (and their
thresholds are set relative to) the Threshold parameter.

Gain Reduction Meter

As input signals exceed the Threshold, the rightness character in the bargraph is lit, and
successive characters are lit for each approximately 3dB in gain reduction imposed by
the compressor on the input signal. Because this is a compression meter and not a level
meter, the same input signal level will show widely varying meter readings depending
on the setting of the Ratio parameter.

Ratio

Sets the ratio of output signal to input
signal levels, selectable in 16 steps
from 1:1.1 to 1:INFINITY.
When Neg Compression is set to
Enabled, the range of compression
ratios extends beyond INFINITY to
encompass negative compression
ratios from 1:-100 down to 1:-1,
which can be useful for applications
like ducking and other special effects.
See the discussion of the Neg
Compression parameter on

Attack

Sets the amount of time that the compressor's level detector will take to respond to an
increase in signal level. The Attack range is adjustable from Instantaneous (essentially a
peak detector that follows individual samples) to 10 seconds (useful for long-term
leveling or automatic mixing applications.)

Release

Sets the amount of time that the compressor's level detector will take to respond to a
decrease in signal level. The fastest Release time is 100 microseconds, useful for some
special effects but highly prone to distortion; more typical release times are in the range
of 70 milliseconds to 1 second. Release times up to 10 seconds are available for long-
term leveling or automatic mixing applications.
E-MU PCI Digital Audio Systems
0dB
Threshold: -30dB
-30dB
page 96.
-80dB
Core Effects Descriptions
1.1:1
Tip: A ratio of Infinity:1
1.5:1
combined with high
2:1
threshold and fast attack/
3:1
release results in an
10:1
:1
effective peak limiter.
5 - Effects
91