I recently need to play my computer sound to my audience through youtube live.
By default, on Mac OS, you can only select build-in microphone as the audio input.
Then I found this solution.
Download and install Soundflower.
Then run Audio MIDI setup, create a new multi-output device.
![](https://www.dengnz.com/wp-content/uploads/2018/06/image-7.png)
Now go to system sound preference, set the multi-output device as output.
![](https://www.dengnz.com/wp-content/uploads/2018/06/image-6.png)
Then set this multi-output device as google handout's input. You are done.
But, you will notice that you cannot tune the volume any more.
![](https://www.dengnz.com/wp-content/uploads/2018/06/image-8.png)
You have to use these two slider to adjust the volume.
![](https://www.dengnz.com/wp-content/uploads/2018/06/image-5.png)
But last thing, you computer sound will be played to your audience, but your own voice will not. Your real micphone doesn't send audio through google handout.
Here is a workaround, use this lineIn app to redirect your microphone to multi-output device. You are all good to go. You can mute your mic using it too.
download from https://www.macupdate.com/app/mac/11333/linein
![](https://www.dengnz.com/wp-content/uploads/2018/06/image-4.png)