06-13-2018 09:43 PM
06-14-2018 11:39 AM
When the T3i detects that a self-powered external microphone is connected, it should automatically switch over and disable the internal microphone.
Since this does not seem to be occurring I recommend resetting the camera's setting to default to see how it responds. The settings can be reset by following the instructions on page 176 of the camera's manual HERE.
For further assistance with this I recommend contacting our Technical Support team HERE.