The Jaw & Bending
Grab a harmonica that you're comfortable bending on. Perform a bend on hole 2. Note your jaw position in the bending process. Play that hole again... move your tongue into position so that you're ready to bend... but don't bend just yet. Now start to bend... just a little bit... not all the way down... now drop your jaw. You'll notice that the note will bend deeper. Now grab a harmonica where the 2 draw bend is difficult for you to achieve the full depth of the bend. Bend the 2 and to reach a lower degree of the bend now drop your jaw. You may want to use a chromatic tuner to see the pitch as it changes.