7
• Setup and Live Modes of Operation
AFT-24F2M
LIVE MODE
The SETUP mode is used to detect and
remove feedback problems while the
audio system is being checked before a
performance begins.
4. Increase the microphone gain through
the mixer until feedback occurs. The
feedback terminator will automatically
detect and remove the feedback by
inserting notch filters of appropriate
frequencies.
3. If all LIVE filters are exhausted and a
new feedback occurs, then the oldest
LIVE filter is reset and reallocated to
filter the new feedback frequency.
3. To start the setup mode, press the
CLEAR/SETUP button on the front
panel for more than 3 seconds and
release it only when the knob LED
start flashing, indicating that SETUP
mode has been selected.
4. The filter selection in LIVE mode also
depends on the setting of MODE
switch.
2. Ensure that the lock switch on the rear
panel is in OFF position.
6. Exit from SETUP mode by quickly
pressing and releasing the button
once (make sure it is released in less
than 1 second). All filter values will be
stored and their LEDs will be ON.
5. Slowly raise the gain until feedback is
suitably reduced.
7. Now keep the lock switch in ON
position so that the terminator settings
are not disturbed or changed during
the programme.
SETUP MODE
1. Turn ON all the microphones and turn
OFF all other input sources, if any.
2. Ensure that the lock switch on the rear
panel is in OFF position.
LIVE mode is used to detect and remove
the feedback problem in real time i.e.
during the programme.
1. All unused filters left in SETUP mode
can be used in live mode. These
remaining filters are automatically
detected and removed whenever any
f e e d b a c k o c c u r s d u r i n g t h e
programme.
5. The mode switch selects the width or
sharpness of the notch filters. If it is a
musical performance, this switch may
be set in high Q mode ie.1/80th
octave.
6. For speech applications this switch
may be set in low Q mode ie.1/5th
octave .
+3
+2
+1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
d
B
u
700
750
820 850
900
95k
1k
1.2k
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
+1
+2
+3
Hz
Music High 1/80* Octave
Notch Filer Q Diagram
Notch Filter Q Diagram
+3
+2
+1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
d
B
u
700
750
820 850
900
95k
1k
1.2k
Hz
Music 1/80th Octave
Speech 1/5th Octave
