1. Product Introduction.............................................1
2. Product Features...............................................1
3. Main Performance..............................................1
4. Product Structure...............................................2
4.1 AF22 Front panel...........................................2
4.2 AF22 Rear panel interfaces...................................
5. Schematic diagram of conference system connection.................3
6. Operating Instructions for Serial Port Display.........................4
7. Technical Parameter Table........................................8
8. Software Description............................................9
8.1 Software Interface Introduction................................9
8.2 System parameter..........................................10
9. Common Faults and Troubleshooting...............................12
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catalogue
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1. Product Introduction
2. Product Features
3.Main Performance
AF22 AI feedback suppressor is equipped with built-in noise gate, compressor, parametric
equalizer, feedback suppression, high and low pass functions, and has the capability of
automatically detecting existing feedback points. Through DSP system processing of
sound, it can quickly and effectively suppress feedback, effectively enhancing the local
sound pressure and clarity of the amplified sound. Equipped with a 1.8-inch touch screen,
it allows for one-button adjustment, making it convenient for user operation. It is suitable
for use in conference rooms, classrooms, broadcast studios, and other similar settings.
AFC self-learning acoustic feedback suppression: real-time learning of audio environment, precise
suppression of acoustic feedback, avoidance of harsh noise, ensuring stable sound output;
ANS Dynamic Adaptive Noise Cancellation: Dynamically adapts to environmental noise,
enhancing fidelity while effectively reducing noise, restoring clear original sound;
Peak level meter: It visually displays the current amplitude of the audio signal, facilitating
real-time monitoring of signal status and avoiding overload distortion;
Multi-microphone intelligent mixing + microphone selection: Supports multiple microphone
access and intelligent mixing, automatically selecting the optimal microphone Signal, enhance
sound pickup effect;
Rich signal processing modules: filtering function module, including high-pass filter and low-pass
filter, supporting parametric equalization adjustment function, built-in compressor function,
and supporting volume adjustment function;
Support automatic gain control function;
Equipped with a 1.8-inch touch screen, it allows for adjustment of conventional parameters;
1). This device provides 2 channels of universal input, supports 48V phantom power supply,
and 2 channels of balanced line output, with XLR connectors;
2). The input terminal is equipped with a built-in noise gate, compressor, 8-band parametric
equalizer, feedback suppression, and high and low pass filters;
3). 1 output volume adjustment knob;
4). Support AFC adaptive feedback suppression function;
5). One USB Type-A interface, which can be externally connected to a computer for
configuring and adjusting host parameters using PC software;
6). One RESET button, used for resetting to factory settings;
7). Equipped with a 1.8-inch touch screen, with one-click setting for parameter adjustment;
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4. Product structure
4.1 Introduction to AF22 front panel
48V 48V
ON OFF
MIC/LINE IN 1 MIC/LINE IN 2
ON OFF
LOW MID HIGH
SIGNAL LEVEL RESET
RISK OF ELECTRIC
SHOCK DO NOT OPEN
C A U T I O N
MMIICC//LLIINNE I E ON 1UT 1 MMIICC//LLIINNE OE IN 1UT 2
~90V-250V 50/60Hz FUSE: T2AL 250V USB
1 2 3
1 3 4 5 6 7
2
①
②
③
;
Rotary encoder: output volume adjustment;
Power button switch: Turn on or turn off the power;
8-inch touch screen: adjust the conventional usage parameters of the feedback suppressor
4.2 Introduction to the interface on the rear panel of AF22
①
②
③
④
⑤
⑥
⑦
;
Two-channel universal XLR input: MIC/LINE IN input interface, supporting balanced
XLR plugs or 6.5 plugs, capable of connecting to devices such as mixing consoles,
microphones, and handheld conference microphones;
48V phantom power switch: press to activate;
Two XLR outputs;
Input level selection switch: LOW/MID/HIGH;
RESET button: used to restore factory settings;
USB TYPE-A interface: used for connecting to PC software for debugging;
Power interface
AI Feedback Suppressor
5.Schematic diagram of conference system connection
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48V 48V
ON OFF
MIC/LINE IN 1 MIC/LINE IN 2
ON OFF
LOW MID HIGH
SIGNAL LEVEL RESET
RISK OF ELECTRIC
SHOCK DO NOT OPEN
C A U T I O N
MMIICC//LLIINNE I E ON 1UT 1 MMIICC//LLIINNE OE IN 1UT 2
~90V-250V 50/60Hz FUSE: T2AL 250V USB
AI feedback suppressor
OUT
XLR OUT
XLR IN XLR OUT
power amplifier equipment
Conference
Meeting unit
Figure 5.1: Schematic diagram of conference system connection
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6.Operating Instructions for Serial Port Display
1
2 1
2
5
4
3
6.1: Initial display interface upon power-on
Figure 6.1: Interface after power-on Figure 6.2: Loading synchronous mainboard data
Figure 6.3: Initial main interface display Figure 6.4: Pressing parameter settings display
As shown in Figure 6-3, ①represents switching to the parameter setting interface, and
②pressing the parameter setting displays the main interface status; as shown in Figure 6-4,
the main interface is divided into level display, output volume, two-channel input level detection,
and +48V.
Phantom power switch, switching interface;
①: Level display: Capable of dynamically displaying parameters on the main interface;
②: Output volume: Adjust the rotary encoder to update the volume in real time;
③: IN1, IN2 level status detection: Connect a microphone and shout, the level will change
in real-time;
④: +48V phantom power switch detection: Press the phantom power switch, and the
control indicator lights up;
⑤: Buttons: Cannot be pressed in level display mode, but can be switched during
parameter setting;
Figure 6.5: Parameter Setting Interface
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Figure 6.6: MIC Switch Interface
6.2: Parameter setting interface
As shown in Figure 6-5,click to return to the previous interface,and select the
corresponding control box to enter parameter settings.
6.1: Click \"Input Settings\" to enter the input parameter setting interface
As shown in Figure 6-6, it is divided into two MIC settings, with each channel having the
same built-in parameter buttons. Taking MIC1 as an example, indicates to turn
off mute and indicates to turn on mute. Clicking on MIC1 settings will take you to
the next interface.
Figure 6.7: MIC1 Input Parameter 1 Interface Figure 6.8: MIC1 Input Parameter 2 Interface
As shown in Figure 6-7, where the volume of MIC1 is Press to decrease volume
Press MIC1 to increase volume Range: -72 to 0 dB; Noise level: Press to decrease
the level, Press to increase the level, noise level range 6-18, sound feedback suppression
can be turned on/off, and the tail length can be selected from four options: 64ms, 96ms,
128ms, and 192ms The noise function can be turned on/off, and the sound mode can be
switched between rich and bright;
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Figure 6.9: High and Low Pass Switch Interface
6.4 Click on \"High and Low Pass\" to enter the High and Low Pass settings interface
As shown in Figure 6-9, it is divided into two-channel MIC frequency modulation settings, with
each channel having the same built-in parameter buttons. Taking MIC1 as an example, click
MIC1 FM enters the next interface.
As shown in Figure 6-10, the high and low pass frequencies of MIC1 can be set separately.
Press as shown in the interface in Figure 6-11. The frequency adjustment range is 20Hz-20kHz.
If the value is not within the range, a prompt will appear to ask for re-entry. After setting, click
\"Confirm Frequency\", and the corresponding switches in Figure 6-9 will turn on.
Figure 6.10: MIC1 High and Low Pass
Frequency Setting Interface
Figure 6.11: Frequency Modulation
Parameter Interface
6.5 Click on \"System Settings\" to enter the system settings interface
As shown in Figure 6-12, click the \"Factory Settings\" button to restore factory settings;
click \"Synchronize Data\" to synchronize the serial port screen with the motherboard data,
as shown in Figure 6-13. After synchronization is complete, return to the system settings
interface.
Figure 6.12: System Settings Interface Figure 6.13: Synchronize Data Interface
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6.6 Click on \"Mode Settings\" to enter the mode settings interface
Figure 6.14: Factory Settings Interface Figure 6.15: Factory Settings Restoration Success Interface
Figure 6.16: Mode Setting Interface
As shown in Figure 6-16, three modes can be saved. When the system is set to select any
mode, click “Save Settings”,andthen click “Select Preset” to call the saved
parameters. (Note: If a preset is saved for a mode and then saved again in that same mode,
the previous settings will be overwritten.)
7.Technical Parameter Table
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Serial
Number Basic parameter name
1
2 ±0.5dB (20Hz~20kHz)
3 ±2dB (20 Hz~20kHz)
4 >100dB (1000Hz)
5 <0.01% (20Hz~20kHz)
6 ≥100dB (20Hz~20kHz)
7
8
9
10
11
AC 90-250V 50/60Hz
12 535x85x400/0.181
3
3kg
4kg
Technical parameter requirements
1) The input terminal is equipped with a built-in noise gate, compressor, 8-band
parametric equalizer, feedback suppression, and high and low-pass filters;
2) One rotary encoder adjusts the volume of two output channels;
3) Support AFC adaptive feedback suppression function;
4) One USB Type-A interface, which can be externally connected to a configuration
computer and used to adjust the host parameters with an upper computer;
5) 1 RESET button, used for restoring factory settings;
6) Built-in DC18 serial port screen, with one-click parameter adjustment settings;
Basic functions
Gain difference
between channels
Amplitude-frequency
response
Signal-to-noise
ratio (A-weighted)
Total harmonic
distortion plus
noise (A-weighted)
Dynamic range
(A weighting)
Input interface
output interface
Input voltage
Net weight
Gross weight
Outer box size/volume
2 XLR connectors, 1 USB TYPE-A connector
2-channel balanced XLR connector
8. Software Description
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Download the software to your local computer through the provided installation package, and
install it with administrator privileges.
8.1 Introduction to software interface
After the software installation is complete, open the software as an administrator. The
interface is shown in Figure 8.1:
Figure 8.1: Main interface of PC software
1. Settings bar and help toolbar: The settings bar allows for switching between Chinese and
English. The help toolbar allows for viewing the software version and the motherboard
firmware version, and the motherboard firmware can be updated by connecting a USB;
2. Device connection toolbar: Connect to the PC software via USB interface, click on serial
port search and select the port, then click on open serial port to connect for debugging;
3. Effect selection control area: Test mode: used to test the feedback suppressor parameters,
with frequency pass-through enabled and all effect adjustments disabled; Stereo mode:
MIC1 corresponds to output LINE OUT1, MIC2 corresponds to output LINE OUT2, with
two channels independent; Mono mode: MIC1 and MIC2 are mixed before being output
to LINE OUT1 and LINE OUT2, with mono mode being the default; clicking on the right
side of any function will jump to the corresponding function interface;
4. Function adjustment control area: You can drag and select the parameter adjustment for
each effect;
5. Input and output volume control bar: This interface allows for the adjustment of 2-in-2-out
volume and mute switch, as well as real-time display of phantom power switch and signal
detection;
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8.2 System Parameters
8.2.1 Noise Gate
Threshold: Signals exceeding the threshold pass through, while those below the
threshold are activated and attenuated.
Activation time: Activation time refers to the speed at which the noise gate opens.
Release time: Release time is the opposite of attack time, referring to the speed
at which the noise gate closes.
Figure 8.2: Noise Gate Interface
8.2.2 Compressor
Figure 8.3: Compressor Interface
Threshold: When the signal level exceeds this value, the compressor begins to reduce
its gain. Any signal exceeding the threshold is considered an overshoot signal, and its
level will be reduced under normal circumstances. The greater the extent to which the
signal exceeds the threshold, the more its level will be attenuated.
Ratio: refers to the compression ratio. The ratio determines the degree of attenuation
of the overshoot signal towards the threshold level. The smaller the compression ratio,
the easier it is for the signal to exceed the threshold.
8.2.4 Feedback inhibition
Figure 8.5: Feedback Suppression Interface
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Attack time, release time: To preserve the natural onset sensation, it is usually desired that
the initial part of the level passes through the compressor unaffected (or only slightly affected).
The buildup time determines the speed at which gain attenuation occurs, while the release
time determines the speed at which gain recovers.
Output Gain Slider: If the compressor significantly reduces the signal level, it may be necessary
to increase the output gain to maintain the volume level. This increase applies uniformly to
all parts of the signal, regardless of the settings of other compressor parameters.
8.2.3 Parametric equalizer (PEQ)
Figure 8.4: Parameter equalization interface
Frequency (Hz): The center frequency of the filter.
Gain (dB): The gain increase or attenuation value in decibels at the center frequency position.
Q: Quality factor of the filter. The adjustable range of Q value is 0.02~50.
Each segment of the equalizer has a switch below, indicating whether it is turned on or off.
When turned off, the parameter settings for each segment do not take effect. The equalizer
has a master switch, indicating whether the module is enabled or disabled.
9. Common fault removal
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Tail length: The tail length can be adjusted.
Noise suppression: Levels 6-18, capable of handling some stable noises, such as air
conditioning and fans.
Howling suppression: On/Off.
Sound mode: You can choose the sound mode, either rich or bright.
8.2.5 HighPass & LowPass Filter
Figure 8.6: High-low pass interface
Frequency: The cutoff frequency of the filter.
Switch: It allows you to turn on or turn off the corresponding high-pass or low-pass effect.
1. Unable to power on
The reason for the computer not being able to turn on may be that the power outlet is not
powered on, or the adapter is not plugged in properly. You can try using another.Check the
device to see if the power outlet is powered on; verify that the adapter plug is
into the power outlet.
fully inserted
2. The connection feedback suppressor is silent
First, check whether the microphone requires phantom power. If it does, press the phantom
power switch for the corresponding channel. Next, check.whether the input and output gain
is adjusted too low or whether the mute switch is turned on.




