dbx PX User Manual page 28

DriveRack PX
Section 5
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Detailed Parameters
AFS On/Off
Turns the AFS module on and off. If AFS is Off, the filters are bypassed, and the algorithm
is halted (the filters are not updated). If AFS is On, the filters are active, and the they are
updated according to the current selected mode (Fixed or Live).
Clear Live/All
This parameter clears the filters. If Clear Live is selected, then (if invoked) the live filters are
reset. If Clear All is selected, then (if invoked) all of the filters are reset. When either Clear
Live or Clear All is selected, the third parameter row displays "Start w/ Data Wheel." If Clear
(none) is selected, then nothing is displayed on this row. When the user moves to this third
row and turns the Data Wheel (when Clear Live or Clear All is selected) then the filter reset is
invoked.
Mode - Live or Fixed
When the mode is Fixed, the algorithm updates only the fixed filters. When the mode is
Live, the algorithm updates only the live filters. In FIXED mode, the filters are automatically
assigned to a frequency creating feedback, thus remaining at that frequency until cleared by
the user. Fixed mode is used before the performance without any input signal. In LIVE mode,
the live filters automatically detect and remove feedback during the performance. When all
of the live filters have been used, they begin to round robin. Essentially this means that the
first filter set is replaced where a new feedback is detected and notched out. This mode is
useful because feedback frequencies may change as the microphone is moved, and/or as the
characteristics of the venue change.
Type - Speech, Low Music, Medium Music and High Music
If Fixed or Live mode is chosen, the text will read "Type." The options will be Speech, Music
Low, Music Medium and Music High. These types pertain to the Q, sensitivity, and algorithm
type. Values are: Speech (Bandwidth = 1/5 octave and Q=7.25), Music Low (Bandwidth = 1/10
octave and Q=14.5), Music Medium (Bandwidth = 1/20 octave and Q=29), and Music High
(Bandwidth = 1/80 octave and Q=116). Note: To guarantee that feedback is suppressed at
lower frequencies, the AFS may place wider notch filters at these lower frequencies (below 700
Hz).
Number Fixed - 0-12
This will range from values 0-12. The total number of filters will stay at 12, and the number
of live filters will be = Total Num Filters – Num Fixed. If this is changed before the filters
are reset, then the filters will be reset one by one as the number changes. For example, if
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