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DRAWMER
Noise Gate Operation
There are circumstances when the programme
material is corrupted such as, in a multi-miked
drum kit setup, some hi-hat will inevitably leak
into the snare microphone, some snare drum into
the kick drum microphone and so on. Equally, on
location, you may experience problems due to
wind or traffic noise or close-by conversation. If
the unwanted noise is different in pitch to the
wanted sound, it is often possible, by using the
Key Listen facility, to use the filters to ‘tune’ in to
the wanted sound while excluding the unwanted.
With signals having a naturally slow or moderate
attack, setting the gate attack time too fast can
cause clicks, particularly if the threshold has to
be set high because of excessive background
noise, especially with the audio signal in lower
frequencies (eg bass guitar, bass drum). With a
high threshold, a low frequency sine wave will
be ignored as the signal starts from its zero level
point, as this wave climbs towards its peak, the
level will suddenly exceed the threshold setting,
at this point a very fast attack rate will switch the
signal through the noise gate with such a steep
( a l m o s t v e r t i c a l ) l e a d i n g e d g e t h a t t h e l o w
f r e q u e n c y s o u n d w i l l h a v e a s i n g l e h i g h
frequency square wave added to its first cycle, in
other words a ‘click’ will be heard. In cases like
these, start with a fast attack time and moderate
threshold, then gradually lengthen the attack time
until the audible click just disappears when the
gate opens, unless the ‘click’ is being added as
an effect!
Ducking
P r o b a b l y t h e m o s t c o m m o n f o r m o f D u c k i n g i s t h a t u s e d b y r a d i o
announcers, whereby the volume of the music being played is dropped,
enabling them to speak over it. In Duck mode the music signal is routed to
the input and the announcer’s microphone signal is the key source ( set
‘Source’ to ‘External’ and plug in the mic signal via the jack).
The Range control is used to set the level to which the music will drop duck
is triggered, and the envelope controls determine the rate at which the level
Gating Vocals
