Yamaha DTXpress/DTXplorer/DTXtreme

Hi again...I forgot to post this question (please forgive me as my 
computer has been in sick bay for a week, it just got fixed and I 
have some catching up to do on this group).  When I hit my HH, the 
snare will also give off a low pitch sound...what am I doing wrong, 
and what needs to be adjusted to fix this?