Applies to: All Focusrite audio interfaces

This is a guide to setting up your audio interface in Open Broadcaster Software (OBS) on a Mac. For instructions for Windows computers, please see the following article: Setting up your audio interface in OBS on Windows.

We are aware that there is a limitation with OBS on macOS, which means all inputs on the interface (including Loopback) are summed together. Please see All of my interface's inputs are summed together in OBS on macOS for a workaround.

OBS is a free program that allows you to stream audio and video to online platforms such as Facebook, Twitch, and YouTube.

The video below explains the same steps as the article:

To start, navigate to the OBS website and download the compatible version of OBS software for your system.

Setting the audio interface as the audio device

Once downloaded and installed, open the OBS application. If you're running macOS Mojave/Catalina, then please ensure you grant OBS access to the “Microphone” as per the steps in this article, otherwise you'll get no audio.

With your audio interface connected, please navigate to the Audio Mixer > Mix/Aux > Click the Settings button (small gear cog symbol) > Properties.

Select the audio interface you wish to use from the Devices list and select OK.
If you are using the Scarlett Solo or 2i2 4th Gen then please untick Enable Downmixing 

Once you have set your audio device in the properties, you can then exit that window and navigate to the Advanced Audio Properties tab from the Settings menu.

Please make sure you have the mono setting ticked in the advanced audio properties. This will ensure that audio is heard by your audience on both sides of their headphones/speakers.

Once this is set, you can start to add different elements to your stream windows, e.g. screen capture, text overlays, live video feeds, etc.

Adding Sources

From the Sources menu, click the + symbol to add a new Source.

You can then add your incoming audio from your audio interface to the Sources so that your audience can hear you. Please select Audio Input Capture from the Source menu, select Add Existing and the Mic/Aux channel, and click OK.

After this, you can add other Sources if you wish. Display Capture allows you to show your audience what is happening on your screen, which may be helpful when broadcasting things like tutorials. Video Capture Device allows your audience to view the feed from a webcam.

Once this is set up, you will then be able to broadcast both your webcam, computer screen and incoming audio from your audio interface.

Sharing audio from your computer

There are a couple of ways you can route audio playing on your Mac into OBS, and the method you choose largely depends on which interface you have and how many inputs you're looking to use.

We are aware that there is a limitation with OBS on Mac, which means all inputs on the interface (including Loopback) are summed together. The method below details a workaround using a third-party software so that computer audio can be separated from the physical inputs on your interface.

Method 1. Use a third-party application such as BlackHole by Existential Audio.

Install BlackHole 2ch from https://existential.audio/blackhole and select it as your Mac's audio output device.

Open OBS > Settings > Audio > Global Audio Devices and select BlackHole 2ch under Desktop Audio. Click Apply and then OK.

Click the + icon in the Sources section and select Audio Input Capture.

Name your Audio Input Capture and click OK.

Set the Device to your interface and click OK.

Monitoring your audio

Navigate to OBS > Advanced Audio Properties within the Audio Mixer section. Each source has an Audio Monitoring setting; set this as appropriate. You'll need to monitor Desktop Audio through OBS if you want to hear the audio signal.

Method 2. Use a ¼ inch jack to jack cable to connect a line output on your audio interface directly to a line input on the interface. This method is better suited to our larger audio interfaces, where you have spare outputs/inputs you can utilise. It allows you to create separate mixes of audio for what you hear in your headphones/speakers and what the audience is hearing, and is explained in the articles below.

Focusrite Interfaces that use Focusrite Control: How to use several inputs on your Scarlett (2nd/3rd Gen) or Clarett interface within video call software on Mac

Focusrite interfaces that use Scarlett/Saffire Mix Control: How to create a Mix suitable for Video Calls, Conferencing, and Lesson Calls/ for 1st Gen Scarlett or Saffire

Streaming

Once you have set up OBS, you can then live stream directly to your chosen platform by going to Preferences > Stream and entering your Stream Key. An example of how to do this with Facebook Live can be found below.

https://obsproject.com/forum/resources/how-to-stream-to-facebook-live.391/

Note Audio/Video Sync Issues

If you notice that your audio is not syncing up with your video, you may need to apply a sync offset to synchronize them in the Advanced Audio Properties. You can adjust the Sync Offset value in milliseconds. The exact value you set depends on how your computer is processing the audio and video, so you will have to experiment in order to find the right value.