I see/hear people playing Andes music on larger wooden whistles. I like the deeper tone ( not shrill) produced by these larger wooden whistles. Are these considered tin whistles ? Mine is brass and produces more of a shrill sound which my wife hates ! 
To get a deeper toned whistle do I need to buy this larger wooden one ?
If you bought a āregularā tin whistle it will be in the key of āDā, maybe āCā, these are soprano whistles.
The next step is to a lower keyed whistle, but these are more expensive, & usually come from specialist makers.
The best solution would be to listen to the various keys of whistle on Youtube, to get an idea of what would suit you.
Having said that, there are also recorders & Native American Flutes (which are actually like a whistle), too.
My own preferences are for the lower keyed whistles, from āCā down to low āDā, however, as you go lower, the finger spacing increases, which may be a problem, so think carefully. 
My wife does not like the sound of the soprano D either. But thatās less and less true as I get better at it.
āTinā whistles can be made of wood, or aluminum, or plastic; they are just called tin whistles because mass market whistles were made of metal. Personally, I donāt think the material a whistle is made of has much effect on the sound: I think its all about the mouthpiece and the tuning. But lots of people disagree about that.
As mentioned whistles come in a wide variety of sizes and key signatures/ranges. The Low D whistle is a tin whistle, an octave lower. itās close to two feet long. Also as fatmac said the holes get harder to cover as the whistles get bigger
You can find whistles in Bb, or A, or G, or F, and they will have a less shrill sound
Can you play a song in D major using a low D whistle using the same finger positions ?
Yes (although itās generally referred to as a tune ifān thereās no singing involved.)
Best wishes.
Steve
yes.
You can learn a D tune on a regular D whistle, play the same tune using the same fingerings on a low D whistle, and it will be one octave lower.
You can play the same tune on a C whistle, using the same fingerings, and it will be in the key of C.
Whistles are known as ātransposingā instruments. Basically, if you wanna play a tune in a different key, you can play it on a differently keyed whistle rather than learning new fingerings. Itās like capo-ing your guitar.
Thank you and as a new player I sure didnāt know that !!!
Where they actually whistles or where they QUENA flutes?
Dear Yankees1,
As of Andes music thing,
I believe youāre talking about a quena (flute) or a quenacho (flute).
And I guess your brass whistle is in the key of D (soprano) !
So thereās as a standard letās say:
soprano (the one your wife hate),
Alto (little deeper),
Tenor (the one you like I guess),
Bass.
If that Andes flute (which you called it a whistle) a large deep instrument, then thatās a Quenacho (in the key of DāLow/Tenor).
If itās a medium sized instrument, then thatās a Quena (in the key of GāAlto).
In the world of whistles,
you are looking at an Alto whistle in the key of G,
Or a Tenor/Low whistle in the key of D.
** if you are a beginner, I guess the Tenor/Low D whistle will be a stretch for youā¦
** the Alto whistle in the key of G its in the middle of allā¦ So itās the better option for you (just my opinion).
Hope that helpsā¦
Thanks,
Enjoy
I have whistles in low D, low F, low G, A, Bb & C that I use the most, (plus all the high ones up to high G).
The ones I play the most are the low F, the A, the low D, & the C, in that order of preference - anything including & lower than the āAā is acceptable in our household.
My suggestion would be the low F, I bought mine from Shearwater Whistles, & it wasnāt very expensive, worth taking a look.
Maybe he means an Andes whistle, like he says?
They have plenty of fipple-flutes there.
Thereās the Tarka, explained and played here
https://www.youtube.com/watch?v=3Icptg5uzYE
Well that was on a stage, here they are being played in the mountains
https://www.youtube.com/watch?v=Qdes_yDi5rc
and another Andes whistle, the Moseno, here being explained and demonstrated
https://www.youtube.com/watch?v=uHl0ezo32fg
and here as used in actual performance
https://www.youtube.com/watch?v=RcGgkMnsLIU&list=PLyURUzWW0CZvsLeBI2Yj-gLocoalznpQn
The similarity of this to the Romanian Caval is striking.
https://www.youtube.com/watch?v=R0jQgTcfpF4
But if the discussion is about Andean flutes like the Kena, yes, it fingers like an Irish whistle but has a thumb-hole.
I suppose you could drill a thumb hole (for D, not C) and then you could use Kena fingering on an Irish whistle.