Using 2 sound cards

Bad news I'm afraid I've never seen a program using more than one soundcard at a time. I've tried with both internal and external (PCI and firewire daisychained) and neither seem to work on nuendo, as far as I know the only way you can do this is using one card as an input and one as an output, but the bus cannot take an input from or output to two sperate soundcards at the same time.

There are programs (like nuendo) that can output to different outputs once you set up the audio bus settings, I dont know Live or Serano Scratch but I'm assuming that if they are professional programs you should have this option.

Microsoft only supports one active output device at a time. You can technically use two different soundcards for two seprate programs (Assuming one of those programs allows you to manually set a non-default sound device as the output), but I don't know of any way to do what you want to do.

Some professional DJ software supports two sound cards, one intended for monitoring. Probably because lots of DJ software producers are also selling hardware like their own sound cards, and appropriate DJ controllers off-course.

Got personal experience quite long time ago using VirtualDJ Professional that allows the dual sound card.

Check the features of your DJ software.

Yes, I think I have seen this option but have never tried it. Routing the monitor/headphone mix to a different soundcard and the main mix through the second, that would work just great. Thanks, then I will actively try to pursue this setup and will let you guys know what issues arise.