Other than performing a small bit of the “thumb tweak,” I don’t know enough to do more extensive modifications. I found that I need to be more conscious of sealing the mouthpiece with my mouth than I do with my other whistles. Especially in the upper register. If I do that, the airiness all but disappears.
Deb
My first whistle was an Oak brass d so I had nothing to compare it too. After awhile I started to think it had shortcomings so I started my trip down the road of whistle accumulation and quickly wound up with a Dixon Trad, Jerry’s d/c pair, a Jerry Gen Bb and Becker d, c, and Bb. Compared to just about anything, whistles are so inexpensive,it’s painless to whip out the plastic. Now when I practice, frequently I wind up playing All of them, so I’ve learned what others above are saying . They all sound really fine. Some sound better than others on certain tunes and certain keys. The Oak is the quietest and for me easiest to play, most suited for practice - easy on my and my wife’s ears. The ‘shortcomings’ of the Oak were from the nut behind the wheel - me trying to play too fast ! I’m enjoying all of the whistles but I’ll never let go of the Oak (tweaked) - my first love. I’ve just ordered an Oak c - Amazon $12. It’s been a great trip so far !
New member here. This is my first post after lurking for several months. I’ve been playing the whistle for about a year and have been frustrated with the Feadog Pro D (nickel), although I like the tone compared to the Gen D (brass).
After reading many whistle discussions and recommendations from this Forum, I ordered a Dixon Trad D (brass). It came today and I am extremely happy with this whistle. I did not have to get used to it at all and I could play all of the notes much cleaner and consistently than the Feadog. The response on the Trad is very good, too. My only complaint is that I can’t seem to put the whistle down to get some work done.
Anyway, this is a great Forum for many topics, and the whistle reviews and discussions were very helpful. The Dixon Trad D works for me.
Thanks,
Poppi
I have the Freeman-tweaked Blackbird (D) and the Freeman-tweaked Mellow Dog C/D set. Other than that, I have 7 of the $5 “Mel Bay by Clarke” whistles in a pretty red color (one of them is blue). 
I love the sweetness and clarity of the Blackbird, and the fact that it doesn’t make me dizzy to play it 
, but it’s starting to get a bit squeaky on me…not sure why. The Mellow Dog C is absolutely wonderful! I think I am addicted to that whistle. I’m still getting the hang of the Mellow Dog D (takes a lot more breath than the Blackbird to get to the upper register), but I love that one too–both are louder than the Blackbird in D. All the Freeman whistles I own have been enjoyable to play, and the price is pretty good! The Clarke whistles are also pretty good, for a children’s instrument (my children use them for learning music theory, and I pack one in my purse for practicing at odd moments). They are much breathier sounding, though. But still quite playable.
thanks everyone for the suggestions. I think I’m going to stick with the oak whistle for a while and work on improving my skills before I look into making a purchase I may end up regretting… I knew that there were a lot of whistles, but like someone said earlier, it sounds like a got almost a different response from everyone. I’m going to keep researching and playing and see where it takes me from there
Actually (I don’t know why I didn’t think of this before)…
You should read through the following thread. It is my all-time favorite thread here on the whistle forum.
https://forums.chiffandfipple.com/t/of-cheapies-and-high-end-whistles/55304/1
Make sure you read through the entire thing. Not only will it reaffirm your decision, but it’s one of the most entertaining threads I can remember.