I've seen this arrangement for "Californication" (guitar fingerstyle). I'm don't know how to thumb slap well, but I'd like to understand how the slap works here.
For example, look at the first slap in the video at 0:11, He is slapping the E string but which strings should I hit while slapping? What do the "X"-s in the tab mean? I googled and I think it means "to mute", but how should I do that (if that's the correct meaning of the "X")?
After investgating and not understanding, It seems like the only notes that makes sound is the one I marked in red (D string, fret 0), so is this muting? If so, how is it done?
p.s. I tried hitting the 3 bottom strings (marked with X) as I slapped the low E with my thumb, the sound I got was clearly not the right one, which again makes me thing this is muting, so I'm still left wondering if indeed this is the case and how should I mute if it is)