Yamaha DTXpress/DTXplorer/DTXtreme

Ok I'll own up I'm lazy, I've had the drum kit at 12pm today and 
played it for 9 hours non stop. I've read about layering the sounds 
on the pads to make them more dynamic, so how do you do it?, I'd 
rather find out by someone human rather than the manual which is 
usually confusing.

Also I find that alot of the time today the bass durm would decide to 
go quiet every so often for no apparent reason without me fiddling 
with any settins, and coudl only be restored with the factory preset 
option, bit of an annoying bugger!

Cheers