I've had a few opportunities to play with a Low D, and they're wonderful if you can.

Note that this is a BIG whistle. Most of the ones I've seen are around 2-3 foot long. My personal favorite is the Clarke Low D - it's stainless steel or aluminum (think it's steel), and probably weighs in at around 5-10 lbs... I keep telling my band that if we ever get involved in a bar fight, I can lead the way swinging with the whistle.

They do take some getting used to. Spacing's about twice that of a normal whistle, and transferring between the regular D and low D takes me a few minutes to get used to.

Good luck with it, though. It's a beautiful sound, and blends VERY well with other winds, esp. flute...

M