I don't own an XP30, but do own an XP80, so this may help:
Set the PERFORMANCE's Effects Output (Assignment) to PAT. Then press the RHYTHM button to call up the drum kit and adjust the "verb kick" drum's Reverb Send Level to zero and you should have a dry kick (as dry as a "verb kick" can sound!)! Be sure not to lower the final output ("Reverb Level")level as this will change the reverb output level for the entire performance. Also, if you don't save the drum kit to user memory, the kick will be wet with reverb the next time you use it. Just be careful with your user memory; don't erase something you don't want to. I've lost nearly an entire song - user (personally programmed) patches, user rhythm loops, and user drum kit - when I overwrote my user memory previously...it is a horrible feeling when you realize you've lost it all permanently!
I don't know about the SmartMedia cards, but a 1.44 meg floppy will hold a ton of user patches, performances, and kits.
Hope this stuff applies to the XP30 as well! Good luck!