I recently picked up a tin whistle, and everything is fine except for one thing. In all the Irish songs in D, they use the last three holes (farthest from the mouthpiece), and still manage to play it loudly. Now, my problem is that most of these require you to play the lower octave of the first three holes, which is either impossible to do, or I'm just not breathing the right way. I can get it, but it's so soft you can't even hear it. I know that they don't just use the higher octave on the last three, and use the normal key on the first (blowing harder on the last ones, and normal on the first ones), because it doesn't squeak or sound awful.

Any help would be appreciated.