Yamaha DTXpress/DTXplorer/DTXtreme

Hello persussion enthusiast,
I have got a new DTXPRESS II kit couple days back.

I am using my logitect z 680 as speakers.
For some reason the actual pad ( when I play) volume are not sounding 
at the same level as the built in song accompaniment drum sounds.

I have tried increasing the snare and kick pedal volume but it does 
not even reah half of the drums sounds in songs

Please enlighten me!

Thanks
--Amit