Since the design of my new whistles is still not set in stone, I thought I’d request some feedback regarding your preference in tunable whistles.
I personally prefer a movable head instead of the more traditional tuning slide.
I wonder if I’m among the minority though, since most high-end whistle makers opt to use a tuning slide.
It makes more sense in my mind to use a movable head, since even a thin brass tuning slide will produce an irregularity in the bore of the tube.
I know that in whistles where the tuning slide is a simple cut in fairly thick tubing patched back together with an outer sleeve, the irregularity created in the bore causes some very strange intonation problems.
I am certain then, that even a very thin tuning slide would produce some intonation disturbances… even though they might be negligible.
Such problems should be completely eliminated by using a movable head, since the wavelength that travels down the tube originates there.
Anyone care to back me up or correct me on the matter?
I wouldn’t have any complaint with a moveable head as long as it doesn’t make the whistle unbalanced (i. e., is made from very light material). My main complaint with Sindts is the light shaft and heavy mouthpiece.
Has anyone made a comparison of the sound of a maker’s tuneable vs. non-tuneable whistle? Say Overton or Harper, both of which come either way?
I’ve made a small comparition betwen a Tunable and Nontunable Chieftain low D. The tunable one had a tuning slide. I haven’t experiensed any disturbances whatsoever. The tuning is acctually better on the tunable + it can be tuned (obviosly 
). I think that a good solution for a tuning slide would be to make the mouthpiece end as wide as the lower part of the body and then a little wider part on the body (the actual tuning slide) on the top were the head of the whistle is inserted. And then there should be a graceful sloope back to normal width (on the body) and NO sharp edge. Did that make sense?? Thats what I think anyway, but you might want to seek the advice of a professional whistle smith.
I use two different versions of tuning slides. My original is done by turning down the last inch of the (4-inch long) head to 0.018 inches wall thickness (starts out as 0.040), and boring the body tube on the lathe to fit. That makes a nice, sleek slide with very little difference in ID when slid out.
The second thing I do is to build the whistle as a non-tunable, tune it perfectly, then cut the head off 4 inches below the mouthpiece, trim an extra 1/4 inch from the tube, and use an external tube that makes a tight fit, as a slide socket, sweated onto the body tube.
The real answer, though, is that no matter how you slice it, you’re always going to have a difference in diameter between the head and body, someplace, or they simply won’t slide together. And as you change the pitch of the tunable, you’re going to increase or decrease the length of the larger diameter area.
I use a shakuhachi tuner I got from Japan, that shows overtones very nicely, and I see no appreciable difference between the non-tunable newly-made whistle, and the tunable made from it. I’d say build a few both ways and listen and see what you think. The electronics say they’re maybe half a pinch off identical, and I can’t hear that.
Cheers, and best of luck!
Bill Whedon
Serpent Music
Gary
You may have noticed that movable heads are often combined with quite thin-walled tubing (Sindt, Howard… or any hard-boiled cheap plastic-head penny whistle).
With thicker walls (light alloy, PVC) a sharp expansion just after the blade level may be not ideal, being the reverse of the compression effect wanted.
In my opinion, using a tuning slide or moveable head is a matter of preference. The problem most makers have is in the placement. If the headjoint or the tuning slide are located on a harmonic “anti-node”, this can cause a lot of problems with overblowing and intonation.
An “anti-node” is a place of highest vibration for a frequency within the bore. When an irregularity is placed near an anti-node that is an overblown harmonic register of the key frequency, it throws all the other registers “off” (sharp/flat). Calculating the anti-nodes of all 4 usable registers will show “windows” for placement that will not interfere with performance. I will admit that making a moveable headjoint is much easier though.