Thanks - I need to do more where I play the instrument properly because it may have more potential yet than it initially seemed. I'm getting all the notes but the lowest to sound nice sometimes, but it's uncomfortable and I've only just realised part of the reason it may be so awkward: I need to try filing off the spikes to either side of the window to make them perpendicular to the part pressed against my lower lip because they're likely inhibiting the movement of the upper lip.
It does indeed affect things, making the instrument play slightly sharp, but that can be countered using the tuning slide. I'll shape the ramp like on a conventional quena with the next prototype. Interestingly though, when I add a fipple to one of my quenillas or to that modified recorder, it works horizontally regardless of the ramp angles, which is not the case when blowing it with my lips. The jet of air from the windway must just be so much more regular, which is also why whistles create such sweet, pure notes without the same "flute" character.For what it's worth, here are a couple of thoughts I have on this. First, I think the fundamental approach is very much worthwhile. But I think you need to be careful about a couple of small details. One is the angle at which you cut off the top of the tube. Most whistles and recorders terminate the upper end of the bore perpendicular to the axis of the bore. When you cut off the top at an angle and then seal the end with your chin or lower lip, as with a quena, you are slightly modifying the bore length at the head, by losing a bit of bore volume under the window. This might affect things. I'd tend to try to account for this loss by very slightly (proportionately) extending the head bore length, so that the end can still be cut at an angle (which is necessary for ergonomic reasons).
"Second, the air flow that leaves your lip embouchure when playing a quena, or any embouchure flute, is not really the same shape as the flow leaving a rectangular recorder or whistle windway. For optimal tone, you need to really match the shape of the labium edge to the shape of the air flow. The U-shaped labium in a quena is probably not shaped that way by accident! One of the most critical, and finicky aspects of flute making is the embouchure cut, where the minutest details can make the difference between a great sounding flute and a mediocre or poor one.[/quote]
There are quenas with an "escotadura recta" - straight edge to the ramp instead of the usual curve, but they have a reputation for being a bit harder to play. My quenilla whistle adapters though are producing beautiful notes with standard curved shape, and I wonder if that may actually be optimal. If you think about it, the air blown through the middle of the windway should be fastest as it's slowed more to either side by the side walls, so the edge you're aiming at maybe should be shaped to take that into account. It may be that they're normally cut straight here because of the tools that are traditionally made to make them, and the fact that our tradition is to make flutes with a hole on the top rather than having them end-blown, while the ones with wedge shaped ramps, whistles and recorders, are likely done with chisels rather than round files to get a shape the lines up nicely with the windway along the full legth. When you use a chisel for two slopes that meet each other, you get a straight edge. When you use a round file, you get a curved edge. I don't know how they shaped their quenas before European tools arrived though - most likely filing with rounded edges of flatish stones.
Yes, that could be a big problem. With any luck though, I might turn out to be wrong about the poor quality of the lowest notes. I've got pretty good quality out of all but the the lowest note now, though it's really poor. Maybe the fact there are two small holes there instead of one big one is the cause of the problem, or the huge slot underneath it that could be disrupting the air flow, and that's only there to let you rotate it to the most comfortable angle for the length of your little finger. That could be fixed.On the bore profile, I would avoid messing with the body bore profile at the foot, or anywhere else, at least initially. The bore profile and tone hole lattice all work together to enable the tuning of the notes over the full range, including the cross fingered notes and the ones that use higher harmonics. If you mess with the bore profile you throw all this off. It would probably be easy enough to get the low octave notes to work, for example, with a simple cylindrical bore. But if you want to preserve the chromaticity across the full range, then the bore profile and tone hole lattice details really matter, right down to the finest details.
I would have used my treble recorder if I could find it, but I haven't seen it for about 20 years. I really don't like recorder fingering, so I switched over to whistles and quenas and only have a few pieces that I prefer to play on a descant recorder.I do agree that these higher pitched recorders and whistles are harder to play with an embouchure-style head than a lower pitched instrument would be. The reason is the smaller size of the embouchure hole, which has to match the small bore, and the very tight embouchure required from the player, which is very strenuous on the embouchure muscles. Playing a piccolo is much more "heavy lifting" for the embouchure than playing a flute, for example. So, I think your approach would naturally yield much better results when applied to a lower pitched instrument than say a high C or D instrument. Something like a low F might be an easier target.