Hi folks, I was thinking after having chatted about flutes with friends on the Net regarding wood qualities, and behaviour when used for flutes, hobos, clarinets etc. Since we all play the flute I would like to ask your opinion and expérience with cocus and blackwood. My humble thoughts would be that cocus sounds a bit more mellow but that can be also because of the way I blow it. I don’t really know, anyway that’s my opinion. I would appreciate any reaction. Have a good day!
Ron 
Oh no! You’ve opened a can of worms Ronnie!!
To be honest, it’ll probably be different for everyone you ask. There is more to do with the embouchure and bore / tone hole dimensions, I think personally between a good solid aged cocus, and black wood. The thing however there is so many different gradients of the two woods, it’s hard to compare because there isn’t one type of cocus or black wood that is uniform. There is good and bad cocus as is there good and bad black wood.
If you are comparing box wood and black wood / cocus, you may have an easier time differentiating the two, but cocus and black wood - if you had a good example of both, and assuming you could have 2 identical flutes, (which is impossible), I’d say it would more be in the eye of the beholder.
For me personally, a good aged and seasoned old piece of cocus (like the pratten I’ve just put on the market), simply speaks the same language… When you get it right, it just explodes in your hands and resonates with your music.
Black wood seems to me more stable, but at the same time, lacks a little of the meaty frequencies of cocus.
I find the exact opposite of what you said Ronnie. Cocus, for me, is definitely not mellower sounding in anyway. Boxwood yes, but a good solid cocus is everything that Blackwood is, but with little bells on 
However, like I said… This is an annoyingly undefinable argument, as there is no way of measuring two identical flutes from the two materials, because that is impossible! Saturation of wood, the amount the flute has been played in, quality of either of the two timbers, embouchure Cut etc…
No doubt a few makers are going to chip in with scientific evidence here, but the bottom line for me, merely a player, is that there are SO many other factors to take into account, the difference between cocus and Blackwood isn’t keeping me from sleeping at night. It’s the cherry on the cake if you like, if you’ve got an awesome flute, having it made from cocus isn’t going to make it sound worse… Put it like that
Wow, I couldn’t want for anything more in an answer Calum. I was just thinking out loud. As I mentioned, a lot is in how you handle the instrument. A can of worms indeed. Lets stick to what we are comfortable with and muddle on (speaking for myself here). Thanks for reacting, its time I get my bumm down South this year 
Fair bit of chat about cocus in this thread: https://forums.chiffandfipple.com/t/why-cocus/88053/1