The iD24 features two headphone outputs which can be reassigned to various outputs.
This could be for artist mixes, or for checking your mix on multiple pairs of headphones. Please view our other iD24 guides for more detailed information regarding specific setups.
In order to assign your headphone ports to a different output open the iD mixer.
Once here go to "View" > "Show System Panel".
You can now use the routing matrix to assign your headphones as required.