Jim Feeley
Veteran
Does anyone know if the 801 is more sensitive than the 802?
Looks like they're within about a dB of each other. As Rick suggests, drop them a line and ask:
http://www.oscarsoundtech.com/contactus.html
About the different response curves, I agree with what others are saying. There's a bit of info on the Countryman site about the three curves available with their EMW mic (the OST 801/802 has a similar shape) that might be helpful for understanding that (but not related to how "loud" the mic is):

Some more info on that Mic: https://countryman.com/product/emw-omnidirectional-lavalier/
But ya, OST can best answer your question, I think...