String Tension/Action for a new slap bassist

[querry]

so, i'm new to slap bass (like super new) and I had a few questions

So my setup is essentially a p-bass w/ a vintage jazz pu stuck on.

So I'm just starting to try out some slapping, but i don't think i'm getting the right sound b/c when i do slap my string hits the fret which leads to a jarring sound, followed by the desired slap sound. I'm not sure if this sound is normal/supposed to be there and I've just not noticed it in other peoples slapping, or if i'm doing something wrong. I think i'm either a) slapping to hard and slamming the strings into the board or b) my string tension isn't high enough and so the strings fall into the strings more readily.

In either of these cases (or if its something completely different) can you tell me how to fix this?

[chump stain]

Sounds like it may be in your technique. Just have to work the thumb, practice. But set up is important for slap.
I like mine set up with low action, flat neck, and I tune a whole step flat (DGCF). This will turn your bass into a slap machine. With the low action, and softer tension, slapping will come easy for you. With the dropped tuning, you just have to move up 2 frets. A is now the 7th fret of your D string.