I’m new here - so would like to say “hello everybody!” 
I play a whistle not so long - but I’ve played a recorder much longer (for my own pleasure mostly)
I’ve got Feadóg D and I’ve bought the Clarke Original recently. I consider it needs too much air - so I’m determined to tweak it a bit.
I’ll plan to put something flat into a windway and squeeze it - flatten a bit. I don’t know how much I could squeeze it not to make it unplayable. Another issue that concerns me is side material - if I flatten it on top there will be gaps on both sides.
Any suggestion? Or maybe there is some step-by-step do-it-yourself guide somewhere?
Hello to you too, and welcome.
Try here for tweak info;
http://chiffboard.mati.ca/viewtopic.php?t=39229
Here’s the money quote from BrewerPaul,
You can tweak that Clark to make it take less air. The only tool required is your thumb: CAREFULLY press the top of the windway down a LITTLE BIT, lowering the roof of the windway. Test play it (live with it for a couple of days) then do it a bit more if you feel it needs it. If you go too far, you can re-raise the roof with a pocket knife blade.
Thanks a lot!
I’ve search through the forum, but haven’t found it before.
When I read it I found this and I think it’s even more promising.
Do you know how should I make the muffler? where should I groove a groove in the muffler to make a proper “air canal”. between the fipple block and the muffler or on top - between muffler and the tin cover of the windway?
That looks promising.
I’ve used similar things for my Mountain Ocarinas.
I tried a partial blocking of the fipple using a drinking straw with a inverted super acute ‘v’ cut in the middle.
I’ve also tried a partial block of the windway also using a drinking straw.
Both worked pretty well.
In the ocarina’s case the issue wasn’t so much air volume as sound volume. Those things are LOUD, and I wanted to be able to practice at home.
BTW, Mountain Ocarinas are great instruments, but lack the full second octave so needed for ITM.