User Guide
 The AXIS 2191 Audio Module  AXIS 2100 User’s Manual
 46 
Troubleshooting the Audio Module
Note: If you still have a problem after reading this information, please contact your reseller, or 
visit www.axis.com and check the support section for Axis camera products. 
Symptoms Possible causes Remedial actions
No audio controls below 
camera image.
The AXIS 2191 is not selected 
as the external device.
In the camera’s administration tools, click on External Devices and 
select the AXIS 2191 Audio Module.
Wrong camera firmware. Check the firmware in the camera by checking if External Devices 
appears in the camera’s Administration Tools. If not, the camera does 
not have the correct firmware and it must be upgraded.
No sound from the AXIS 
2191 or from a PC trying to 
access a web page 
containing audio content.
Incorrect settings or faulty 
connections.
Check that: 
• soundcard, speakers and microphone are connected
• the Mute button is not pressed
• the Int/Ext switch for the input is in the correct position
• the input and output levels are correct
• all cabling is connected and all power switches are ON
No audio signal from PC to 
the AXIS 2191 when passing 
a proxy server. 
The Post Content Length set 
in the proxy server is too low. 
Set the value of the Post Content Length in your proxy server to 1MB 
or more. You may need to contact your system administrator to do 
this.
No full-duplex function. Incorrect configuration. Check the setting in the camera’s administration tools. 
Sound card does not support 
full-duplex.
For information on how to check if your sound card supports 
full-duplex, please visit www.axis.com and see the support section for 
Axis camera products.
Poor performance. Too many users/clients 
connected.
Try limiting the number of clients allowed to connect.
Low bandwidth. Reduce the available bandwidth by changing to a lower setting in the 
Available Bandwidth selector. Setting a lower bandwidth will reduce 
any break-up in the sound, but will also increase the transmission 
delay. 
If running in Full-Duplex mode, try switching to Half-Duplex mode.
Whining or screeching sound 
from speakers (feedback).
Poor positioning of speakers 
and/or microphone.
Relocate the speakers or microphone so that they do not point 
towards each other, and/or lower the volume.
Poor sound on headphones. Incorrect connection. Headphones can only be used by connecting them to Speaker-Out on 
the terminal connector.
The Power indicator LED is 
not constantly lit. 
Faulty power supply. Verify that you are using an AXIS PS-D power supply.
The AXIS 2191 works locally, 
but not externally.
Firewall protection. Check the Internet firewall with your system administrator.
Default routers required. Check if you need to configure the default router settings.










