One of the most common reason for audio issues is having the stream playing back on the same device that does the encoding. Not only it takes additional CPU resources for decompression, but it may also playback sound of your stream, which leads to echo on the final video.
This happens because normally broadcasters capture device playback sound source and send it over to the stream along with user's microphone source. Since streams happen with a delay, that captured sound gets played back again on user's device again in a few seconds, and this playback is captured by broadcaster and sent to the stream again. This is somewhat similar to what you can see if you place two mirrors next to each other - infinite reflections.
The solution is simple - mute or stop all your players with the stream preview, and the sound will get fixed instantly.
Of course, if you have any questions or concerns, please do not hesitate to get in touch with our 24/7 support team! Click the chat icon at the lower right-hand corner of your screen to ask a question!