Building a really tight mouth-corner (?) was definitely the case for the hard D flavor I favor, and I did indeed find that the my mouth-corners got pretty tired at first. And then, interestingly, when I started playing a McGee I noticed it required even more effort to get the same quality D as what I was used to on my Hammy or Murray (altho’ the tighter you get on the Murray the more “English-horn-like” it can be, which is kind of cool in and of itself). I’m guessing it’s because both the Murray and the Hammy, especially the Hammy, have smaller embouchure holes – almost focusing the airstream by default just by cutting off stray “fluff” outside the blowhole. Meanwhile, the McGee has a blowhole as big as Texas, so … it was up to me to carve out my little corner of it for the hard D I like, and that took more work (and more sore face; for a few minutes after playing I often felt like a freshman during sorority rush!).
Anyway, it’s just my theory. But THAT said, it’s not really that you have to blow so hard on a Hammy – it’s that you CAN blow pretty hard (tightly focused airstream and lots of push) on a Hammy and get a reallly unique, reedy honk that, to me, doesn’t sound quite like any other flute. It’s not necessarily what the flute does, it’s what it can do when pushed, n’est ce pas? And with Hammys that’s part of the fun; they’re buiilt to take it.
Finally, though, sounds like you’re fine in your approach. Different players have different styles and thus get different sounds, from buzzy & barky to dark & rich to wispy & ethereal, out of their flutes. But in most cases, it’s not about blowing hard; do that and you’ll push the flute out of tune fairly quickly (the why of this I do not understand but I’ve heard about it from authorities on the subject and have been surprised myself more than a few times during sessions – especially when I first got the Hammy and was merrily blasting away, albeit incorrectly
, for all I was worth – and then trying to fix it by pulling out the tuning slide farther and farther until the whole flute would go whacko (double
)). It’s more about supporting the tone with your diaphragm and focusing it with your embouchure. A strong steady push (appropriately pulsed of course
) and a well-focused embouchure should do the trick.
And for a truly rock-hard D on flutes that will take it – and the Hammy seems to take it even more than most – you do basically the same, only more so.
That, at least, is what Conal’s & Paul’s playing sounds like to me – a big solid push from the diaphragm, tightly focused, on a flute that’s built to bark big-time.