This tutorial will guide you through the process of how you can use OBS (Open Broadcast Software) to broadcast using multiple displays ie: (Nvidia Surround/Eyefinity).
This is an example of how the default settings using Game Capture in OBS would appear to you and your viewers. Using this guide will allow you to broadcast your center display.
Step 1: Open OBS. At this point you should also open up the game you plan to broadcast and/or record and alt+tab out.
Step 2: Click on Settings > Video.
Step 3: Enter the Custom Resolution Size as your monitor size. In my case, 1920x1080. You can also choose your Resolution Downscale too.
Step 4: Click on OK.
Step 5: Right click in the Sources box and click Add > Game Capture.
Step 6: Click on Application drop-down menu and choose the game you wish to broadcast. You may need to click on refresh if you’ve only just openend a game.
Step 7: Click OK.
Step 8: Now let’s see how it looks. Click on Preview.
So now as you can see we’re now capturing the middle display. For the purpose of this tutorial I have Minecraft in window mode but it will work correctly in fullscreen. But you might want to remove the black bars.
Step 9: Click on the the Source you added. Then click Edit Scene.
Step 10: Point your cursor to the very edge of the game capture seeing the red border liness. While holding Shift. Drag your mouse down until you’ve filled the black bars. Repeat the process for the top.
And there you have it. If you followed these instructions correctly you should now be able to start broadcasting in a multi-display configuration (Nvidia Surround, Eyefinity Setup).