When you load a sample in slicex and start adding markers, they should start allocating to each note from C4, (c4 for the first chop, c#4 for the second, d4 for the third and so on). You can also right click on the yellow markers and you will get a map to midi note option where you can assign a different number (Useful if your 16 pads are not sequential notes). Are you finding that some pads trigger and sample and some do not? I used to have this problem, I use an MPD32 so not sure how your controller works but the standard setting on load is not sequential, however when I change my Midi controller preset to "generic" then pad 1 is c4, pad 2 is c#4 and so on. Once I got that figured out it is super easy and speeds up workflow alot.
