Yamaha DTXpress/DTXplorer/DTXtreme

I have had similar problems and I have fixed it. I tried to do the 
specific rejection and rejection, and I have set the rejection for 
every pad to 6 and spec rej from snare to hi-hat and vice versa to 6 
or 7, not sure. If you go into the trigger setup menu, you can change 
the Mvel and there is a second option on the page. I had mine fixed 
but the snare would mis-trigger and sometimes machine gun. I fixed 
the velocity down to about 50 and set the other option to 1 and it 
fixed that problem. When I get home I will tell you the names and 
values.

-Zack-