Finally, after two weeks of PayPal induced delays I got my Dixon Low D in the mail! I’ve only had it for a few hours, but so far I think it’s a great whistle.
The first time Iplayed a low d was at a session in Ogden. I think it was a Howard, and the grip was a little to wide for me to handle, especially the bottom D. The Dixon is more managable, though I still need to practice my piper’s grip.
The tone is pretty solid and warm. But the bottom D is a bit fragile, but that’s probably due to my inexperience with the backpressure for this whistle. Before now I’ve only really played my Clarkes (D and C), and both require more air than the Dixon, if you can believe that! So it’s a little weird for me to not have to use all my breath so soon. Half the time I take a breat, it’s because I need to breath, not because I’ve run out of air. 
Hopefully I’ll have it down before the next session meet.
I’ve owned a Dixon Low D for a year now, but never noticed that it had any backpressure?
Maybe Tony has changed something during the last year..
Maybe “backpressure” is the wrong word, but I find that my Clarkes take about as much, if not more air sometimes, to play.
Can somebody define “backpressure” exactly?
Backpressure is… well, it’s how much the whistle “presses back” on your air column, I suppose. Another way to say it would be, “How hard do you have to blow into it?”
As for the difference between backpressure and air requirements, let’s take an example. The clarke you mention has a high air requirement, but the backpressure is relatively low. Therefore you blow a lot of air pretty soft to play it. Like a McDonalds’ straw.
And a coffee stirrer would have high backpressure, compared to a McDonald’s straw.
Then again, Dixon has a low air requirement, and low backpressure. And a susato would have a normal/medium air requirement and higher backpressure.
At least, that’s my mileage.
That makes sense, thanks!