Tutorial: Green Room Chat for Remote Production with vMix Call

This quick tutorial for remote producers should enable you to bring guest presenters into vMix via vMix Call and give you the ability to talk to them, and give them the ability to talk to you, without the audience hearing. Then, when the callers go live, the bus will automatically switch and the audience will hear them but they will not hear what's going on outside of the live show.

Let’s call it Green Room Chat. I am sure there is more than one way to do this, but the method I’ll describe below has worked for me.

Setting Audio Preferences

First of all, you want to be sure your settings are ready to go in the audio preferences. Go to settings > Audio Outputs and enable the buses you will be using. For this purpose, we need to enable only two. In this tutorial we’ll use A for Chat and B as the Master, although you can choose whichever buses you prefer.

Click OK, and vMix will restart.

Assigning Audio Sources

After vMix restarts, follow these steps to assign audio sources:

1. Right-click on each caller window and set Audio Source on each caller to bus A (I believe this is the default). 

2. Now send Bus B to the Master. (In the audio mixer on top, make sure the B bus has the M enabled.) 

3. Deselect the auto transition button on the input of each caller.

4. When Caller goes live, make a trigger for caller audio to switch to bus B (do this for each caller).

5. Make a reverse trigger to send audio back to bus A when they are not live Triggers: 

• OnTransitionIn AudioBusOff Call1 A
• OnTransitionIn AudioBusON Call1 B
• OnTransitionOut AudioBusON Call1 A
• OnTransitionOut AudioBusOff Call1 B

Setting Additional Triggers

Next, we have to make another set of triggers to change the VideoCallAudio Source. This will ensure the caller will not hear backstage chatter on bus A while live, but it will restore audio when off-program.

Note that the Value names are different for vMix call audio! Use “BusB” or “BusA” instead of “B” and “A.”

• OnTransitionIn VideoCallAudio Source Call1 BusB
• OnTransitionOut VideoCallAudio Source Call1 BusA

Adjusting Program Audio

One last note: if you want to be able to adjust program audio in the Green Room chat, you can enable NDI output on Program and bring that back in as a source. You can then send that to bus A and have the ability to adjust levels without affecting your main program audio.

Note that if you have callers live plus another source—such as a video roll—send all audio sources through bus B instead of directly to the master. If you do not do this, your callers will not hear the other sources if they are also live at the time.

That should do it. Just be sure that as the producer, you have yourself chatting on bus A not B or you will also go live to program!