Rfx Compressor; Signal Flow - E-Mu 1212M Owner's Manual

5 - Effects
Core Effects Descriptions

RFX Compressor

The RFX Compressor is a full-featured stereo compressor effect which features the standard
parameters available on most compressors as well as a collection of additional advanced
parameters that are useful for more sophisticated applications and special effects:
• Threshold, Ratio, Attack and Release w/gain metering
• Auto-makeup gain
• Adjustable soft knee
• Adjustable lookahead/delay
• Noise gate (downward expander)
• Compressor "tail" expansion
• Program-dependent release
• Negative compression ratios

Signal Flow

The block diagram of the RFX Compressor is shown below.
In L
In R
(& Sidechain)
SIDECHAIN
Note that the effect is split between a signal path and a sidechain path that contains the
compressor's level detectors and gain computation. The signal path of the RFX
Compressor is very close to a "straight wire", with only a delay line and one gain control
element inserted in it. The sidechain contains the bulk of the compressor algorithm and
is responsible for computing the gain control signal. Signal multiplexers at the front of
the signal path and sidechain allow linked stereo compression or split signal path/
sidechain processing.
The RFX Compressor does not have the input gain control that is found on some
compressors. These are typically used to align the input signal range to the compression
threshold. Instead, we've allowed the RFX Compressor's Threshold 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 renor-
malize the compressor's output for the next stage of the signal path.
90
Compressor
Lookahead
0-100mS
SIGNAL PATH
Compressor
Delay
Compressor
Level
Delay
Detector
0-50mS
Attack Release
Auto Release
Input
Mode
Gain
Cells
Threshold Ratio Gain
Gain
Control
Soft Max. Neg. Gate
Knee Comp. Comp.
Out
L
R
Out
Creative Professional