Yamaha DTXpress/DTXplorer/DTXtreme

Hi , rather then use Yamaha pad i use now my acoustic drum with Mesh 
Head and Ddrum trigger , i don't have a good result for now : after 
some change on Gain and Velocity i still have problem to have good 
sensitivity of sound , to have a almost loud snare sound i have to 
hit Real Hard on my snare , i had that even without start changing 
after using Yamaha pad , so i guess there is something to change 
somewhere when you change from clasic pad to acoustic drum with a 
Ddrum triggering ? i remember that some of you used Ddrum kick pad , 
what did you change to have a good sensitivity ?
Thank's
Stephane