Experimental Philosophy is practical philosophy, living on the crest of the waterfall of thought going from philosophy to art, science and politics.
Any philosophical investigation which can be related, even tenuously, to something tangible or sensible, can be the subject of experimental philosophy.
Philosophical experiments often result in part or all of a philosophical train of thought crashing into one of the lesser academic disciplines, like mathematics, physics, chemistry, politics or even psychology.
All of these were once philosophy.