This article will explain how to use Loopback to share pre-recorded audio in Crowdcast. If you don't wish to use a third-party tool, consider the in-browser method.
What is Loopback?
Loopback is a third-party software that enables you to combine audio from multiple sources – including microphones, browsers, videos – and brings that combined audio into Crowdcast.
Who is it for?
Loopback is for those with a Mac who are looking to play music or share a video during an in-browser (rather than RTMP) Crowdcast event or session.
Where do I download it, and is it free?
You can download Loopback and start your free trial here. After 20-minutes, noise is overlaid on any audio passing through an active virtual audio device. Turn the device off then back on to reset the trial.
If you decide that it fits your needs after some testing, you can purchase a license key to unlock Loopback for a single user on one or more Macs.
We've worked with Rogue Amoeba to get you an exclusive discount. Use coupon code CROWDCAST10 to save 10% off of Loopback.
What if I have more questions regarding Loopback?
For questions about Loopback, please contact the experts themselves over at Loopback's Support Center.
How to use Loopback
Once you've downloaded and installed the trial or paid version of Loopback, you'll create a new virtual audio device which will combine audio from your microphone and your desired media playing app(s). Here are the steps:
1. Click the New Virtual Device button to create a new device. Click on the pencil, and give it a descriptive name. Here, the device's name has been set to Loopback and Crowdcast.

2. You won't use the Pass-Thru source which is included by default. Remove it by clicking to highlight it, and then press the Delete button.

3. Add the desired audio sources by clicking the (+) button next to the Sources header. As seen below, the Spotify app source has been added as well as the iMac's microphone device called iMac Microphone.

4. You'll notice the audio levels moving when you start talking through your microphone or playing your music or second audio source.

5. The volume of your audio sources are controlled through each specific source and not within Loopback. For example, if I wanted Spotify to be in the background while I'm talking, I'll lower the volume from within Spotify.

6. The main volume control is located under your Devices.

At this point, the virtual device is now ready for use throughout your system. It will remain available until you toggle it off or delete it even when Loopback isn't actively running.
How to connect Loopback to Crowdcast
Now that you've created your virtual device, you'll need to select it as the input device within Crowdcast.
1. Enter the greenroom using the in-browser method.

2. Hover over your video to reveal the audio/video menu, and click on the gear icon to change your microphone source.

3. You'll then see a pop up where you can choose your microphone. From the dropdown menu select Loopback as your microphone and click Save.

And that's it!
Your Crowdcast events will now contain all of the audio sources you specified. Audio from your microphone and any other apps you've added will automatically be merged together by Loopback into a virtual audio device. Crowdcast will see this virtual device as a normal microphone, and all of the desired audio will be heard by your attendees.
Run through a few tests and listen to the replay. You can also register as an attendee from a different device, so you can hear what your attendees will hear during your event.
For questions about Loopback, please contact the experts themselves over at Loopback's Support Center.
Have questions or suggestions? Email us at [email protected]. Happy Crowdcasting! 🎥