5 - Effects
Core Effects Descriptions
E-MU PCIe Digital Audio Systems
81
Gate
This stereo noise gate is useful both for background noise reduction applications and
also for special effects.
The gate uses an envelope follower and threshold detector to turn on its output when
the input signal is above the turn-on threshold, and shut down its output when the
signal falls below the shut-off threshold. When ”turned on” the Gate passes the input
signal through to the output at unity gain and when “shut off” the Gate silences the
output or attenuates it by an adjustable gain factor. While the Gate is a stereo effect, the
left and right signals are gated in unison, with the envelope follower defaulting to the
louder of the two signals.
In normal operating mode, Gate turn-on is nearly instantaneous when the input signal
exceeds the Threshold level, while Gate Release time is an adjustable parameter. The
effect of the fast turn-on can be enhanced by using an optional 1 millisecond
lookahead in the Gate's envelope detector.
Together with the Threshold setting, tuning the Release time parameter is very useful in
order to achieve the least-obtrusive, most natural-sounding gating effect, which is
highly dependent on the specific program material being processed.
The gate does not offer an adjustable wet/dry mix parameter but does supply a Bypass
switch for effectively removing the effect from the signal path.
Applications
•
Basic Gating
- reduce background noise during periods of low signal level
•
Re-Enveloping
- extreme release time/attenuation can be used to re-sculpt the
signal envelope
•
Drum Gating
- Drum tracks can be altered by adjusting the Threshold to ignore
all but the hardest hits.
•
Punch Enhancement
- high thfast smodest attenuation
perform an expander-like function that accentuates transients
Out
Threshold
Max Gain
Reduction
Lookahead
Release
Gate
1mS
Delay
Signal path = Stereo
Envelope Follower/
Threshold Detector
In
The Gate behaves exactly as a straight wire except when activated by a signal level below the
Threshold (with Lookahead Off).