How to Remove Audio Background Noise in Camtasia

[@adamgreen4336]

In Camtasia, when I record both system audio and microphone audio I get an echo and really distorted recording, like those two sounds are out of sync. When I mute one, the other thats left sounds much better. What can I do to get them synced? Since this way I have to give up on system audio in favour of microphone recording...and would like to have them both together in very good quality. I have a very good microphone, thats not the cause