DOn't know if this is the right forum, but here we go.
So I bought a Laptop today and took a trial on the Rekordbox DJ.
I have plugged in the CDJ-850 in the USB on the computer and everything is fine.
However, I can only use one channel on my DJM-700 for both CDJ according to Rekordbox. When I plugged in the USB from the CDJ, I get two new sound channels (CDJ850 / 2-CDJ850). I can't use both, I can only use one. While on of them is running, the otherone is silence.
Do I need two soundcards for the computer?