If you are using a Virtual DJ Pro, do the ff:
1. Go to Config
2. Go to Sound Setup tab
3. Click Outputs
4. Select Advanced Config
5. Click Advanced Config
6. Click +, add Master, select “Numark N4”, select “Outputs 1&2” for RCA if you are using an unbalanced setup or choose accordingly.
7. Click + again, add Headphones, select “Numark N4”, select “Outputs 3&4” for headphones check Numarks manual or test it one by one.
That’s it.
With Traktor, its the same concept go to Settings, Audio Setup, Select Numark N4, Go to Output Routing, Internal, Select the appropriate out for your master and monitor outputs. That’s it.
If you are using a Windows based computer, you may have to install the driver that comes with the package, with Mac it is simply plug and play.