User`s manual

47
Description of controls (Figure 4-15) is as follows:
Conditional Adaptiation:
For advanced users only. Novice users should keep Filter will adapt set
to Always. The Threshold setting has no effect in this case.
Conditional Adaptation allows the adaptive filter to automatically
Adapt/Freeze based upon Ma
ster Control Panel bargraph levels.
This can be very useful in situations where there are pauses, or
breaks, in the speech being processed.
Hint: Conditional adaptation is useful in maintaining adaptation once
the filter has converged. Motion in the room and air temperature
changes affect the filter’s operation. First allow the filter to
converge in Always and the click on If Normal Output <
Threshold. Adjust the threshold for adaptation (Adapting LED
is GREEN when adapting) by observing the bargraph levels
when the voice is not present; note that the threshold is shown on
the bargraph along with the audio level, and that the bargraph
corresponds with the Left channel audio in the Stereo, Linked
Input Mode selection.
Click on the Clear button if you desire the filter to completely
readapt based upon the new Conditional Adaptation settings.
The Adapting LED indicator shows the current adaptation status of the
filter; if the LED is illuminated GREEN, the filter is adapting, and when
the LED is not illuminated the filter is not adapting. In Stereo, Linked
Input Mode, only the Left channel adaptation status is displayed.
Filter Size: Used to set the number of FIR filter taps in the adaptive filter. Filter size
is indicated both in taps (filter order) and in milliseconds. Minimum Filter
Size is 4 taps, but can be set to as high as 6144 taps depending on
System Bandwidth, Input Mode, and Number of General Filter Stages
settings. Normally, the maximum filter size possible is used in the Ref
Canceller adaptive filter
Adapt Rate: Used to set the rate at which the adaptive filter adapts to changing signal
conditions (mathematically known as Mu). A Mu of 1 x 2
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provides