This set includes one Flute head, one Whistle head and one body .
my question is, does the sound vary significantly by head? is this a good low d for a beginner?
Weeeell, you’ll want a flute player to double-check me on this 
I own two low whistles, myself; a Dixon Low G duo and a Chieftain Low D. I’ve not had any time to practice with the flute head, so I, personally, sound like a sick elephant chuckles but the tone of the whistle is wonderful. Tony does some incredible work, and I would reccomend his whistles to anyone wanting to play a Low whistle and not pay an arm and a leg at the same time. 
I had a sound clip somewhere… of my Dixon Low G… but not sure what I’ve done with it now. chuckles
Slainté,
Daniel
Hi Cramer,
The only Low D I’ve got is the Duo, and I’m not a flute player either, but I have managed to get some nice notes out of the flute set up when I’ve tried.
I didn’t notice any major difference in sound between flute and whistle head, but I’ll try both tonight and listen carefully.
I would also recommend the Duo on value for money, and I’m perfectly happy with this as my only low D.