Yamaha DTXpress/DTXplorer/DTXtreme

Jamyz:
Two things to check for:

Make certain that you are in 'LIVE' mode from the utility section. 
This will give you greater volume.

Check the 'ROOM TYPE' (Also in the utility section, I believe). This 
function sets reverb levels for the entire kit, unlike the individual 
pad settings). There is a setting called TUNNELL which sound like you 
may be utilizing; albeit unknowingly.

Stephen