Welcome to SweetcaseKicks.com, purveyor of fine hand-crafted suitcase kick drums. Sweetcase Kicks are upcycled vintage suitcases, modified, fortified, and electrified for use as kick drums.
I recommend micing the kick as you would any other kick. Still, all Sweetcase Kicks come with an internal piezo pickup installed so you can plug in a 1/4" cable and go (though I do recommend using some sort of pre-amp to raise the impedence). Watch the video and listen to the difference between the mic and piezo in the Green Machine Sweetcase Kick.