Why does putting an audio clip in Simpler with 127 Velocity clip when coming out?

So I load in a kick sample playing at a 127 velocity. If I set the Gain and Volume at 0, it will clip an insane amount. Even if I set the Volume to the defaul of -12db still not even close. I have to bring the Volume down to over -20db for it to not clip.

So how does Simpler work? And why is it doing this? And is there any difference in turning down the Gain knob? or the Volume knob?

And on a side note, a lot of people have told me I need to put my velocity at 127 for my kicks to knock. Is there a difference between turning down the velocity and turning up the gain? As opposed to full velocity and lower gain or volume fader, if they're hitting the same db?