I do not have Traktor, but I seem to recall (from other threads in this forum) that you need to use ASIO for this.
The DSP config will not change the number of outputs available, it just determines how the signals are routed to the speakers, etc.
Also, I seem to recall there being some issues with kX 3538L (not sure about 3538m) and Traktor (using ASIO).
Aside from the above, try using kX ASIO and make sure that the sample rate in the kX ASIO Control Panel and in Traktor match (kX defaults to 48kHZ). Use ASIO 4/5/6/7 for 4 mono outputs (or 2 stereo outputs), and set Surrounder to one of the Direct Path presets (4/5 will be sent to analog front jack, 6/7 to analog rear).
Here are a couple of related threads that you might want to read:
Traktor 3 and external mixer
Setting up outputs for Traktor 3 (audigy2zs)