Yamaha DTXpress/DTXplorer/DTXtreme

This has proabably been answered, but I can't find it. What function 
allows us to increase or decrease pad sensitivity, per pad? I'm not 
completely sure so if you could tell me it would help. Just seems I 
sometimes get the snare to fire lightly when I play the Hi-hat pad, 
or vice versa, and I'd like to decrease the pad sensitivity for those 
two pads.

-Zack-