How do you play loud on a bassoon?

Playing "loud" on the bassoon is all about air support, a good embouchure, and a good reed. You can't play loud if any of them are missing. Typically when bassoon players play loud they want to drop their jaw which causes them to go flat, especially on the low notes, so be sure not to do much change to your embouchure. Loud on the bassoon is mainly caused by air support. A good air stream with plenty of pressure and wind will cause you to play "loud" on the bassoon.