If you want to have callers to your Mixlr broadcast, or if you have a co-host that's based in another location, the best way to add them to your Mixlr broadcast is by connecting an online audio messaging application to Mixlr. You can do this using using Mixlr AudioLink, an audio device that is installed when you download Mixlr.

TIP: if you're unable to find Mixlr AudioLink, see this article for help: http://help.mixlr.com/en/articles/6744079-why-can-t-i-find-mixlr-audiolink

Firstly you will need to set the audio output on your messaging application to Mixlr AudioLink. You can usually find this option under Options or Preferences. This might not be referred to as the audio output in your application - it may also be labelled 'speakers', 'master output' or something else. If you haven't updated this before it will probably have your speakers currently selected here.

Locate this in your messaging application and change it to 'Speakers (Mixlr AudioLink)'.

(In Skype you can find this by going to More > Settings.)

Open the Mixlr app and select the mixer icon to open your audio settings.

TIP: this is accessible from both the events screen (above) and the broadcast screen, meaning you can set up your audio before you start your live event and adjust as needed while you're on air.

Click the arrow by 'Select Source' for either channel 1 or channel 2 (the Mic and Any Input channels) to bring up the list of input options.

Select 'Mixlr AudioLink > Channels 1 and 2' from the list.

When Mixlr AudioLink has been selected you will see it listed as the input for this channel, where 'Select Source' was previously displayed.

Because you have set the audio output in your messaging application to Mixlr AudioLink you won't be able to hear your caller through your headphones or speakers. 

In order to hear your caller you will need to activate monitoring. See this article for how to activate monitoring.