Fresh on the heels of successfully reeding my Gallagher set's drones (with props to Mr. O'Brien's excellent tutelage on "The Heart of the Instrument"), I'm trying to reed my Sky drones.
But as with every prior attempt at reeding this set, none of my bass drone reeds will consistently lock onto a D, in favor of higher partials. With very low pressure they'll reluctantly hum a soft low D that holds for a little while even as I increase pressure, but never for long, and certainly not when I throw the drones on at normal chanter-playing pressure.
I'm using two reeds by Pat Sky as my model for body & tongue length, but those those have the same problem (apparently I've copied them too faithfully? :-/ ). What am I missing, guys? I haven't seen this issue (wrong partial locking in) addressed in any of my reedmaking books or videos.
Gentlemen, you were correct: I needed to lower the reed's pitch and to "overblow" it. Scraping the tongue a bunch more and adding ballast caused it to lock in to a fat, buzzy D!
Now I just need the thing to not clap shut arbitrarily, but that I know how to fix.
mke_mick wrote:Gentlemen, you were correct: I needed to lower the reed's pitch and to "overblow" it. Scraping the tongue a bunch more and adding ballast caused it to lock in to a fat, buzzy D!
Now I just need the thing to not clap shut arbitrarily, but that I know how to fix.
Thanks so much!
--Mick Bauer
Curve the tongue by supporting it centrally along its length, with your thumb, and gently lifting the free end using fingers one and two... when this is done the tongue closes progressively as in the action of a Clarinet reed.This way the flexibility of the whole tongue can be used to help stabilise things.
You should notice with a curved tongued drone reed, when it is pressed shut by your finger in the middle of its length that the free end is still not closed completely onto the body. This stops the reed from Clapping shut under a much greater range of pressure without having the tongue 'set' too high and thus the tone too strong and the air useage too much.
hi mick,try this drone reed design.choose a tube that would normally be too thick in the walls for a good reed.use the node end to fit to the reed seat.split the tongue out reverse style leaving wood under the tongue so no air is passing through.carefully drill out the body still leaving the wood in but reducing the bore slightly.seal the end.then lift the tongue and with a small drill make a hole under the tongue allowing air to pass through the body.this makes for a very air efficient reed,tune then as normal.good luck.allan moller.
Yes, I re-watched your demonstration of that in your part of "Heart of the Instrument." And sure enough, adding a little more curvature to the tongue did the trick.
My bass drone reed is now stable across both octaves and nicely in tune on D, with the tuning slide about half way out, right where I like it. Thanks again, Geoff!
Allan: just saw your post. Thanks! I'll try that design next time for sure. I've been wondering about the "reversed bass" drone reed concept, which I've seen in composite reeds (e.g. EZ-Drone).
Regards to all,
Mick
Last edited by mke_mick on Mon Jun 10, 2013 7:57 am, edited 1 time in total.
I was reading an article on how Kalimba players can tune the overtones of a note by filing away some metal in certain places on the prongs of the instrument.
The first question is , would the vibrational modes of a kalimba prong be the same as the tongue of a drone reed and if it is could the same techique be used to alter the tone of the drone reed /drone.
Heres the modes of the kalimba prong, but would the tongue of the drone reed ,even though it beats against something rather than free to vibrate back and forth have the same modes?
So for instance if you want a very fundamental based sound would you leave the tongue fairly thick. If you wanted a richer fuller sound you could either cut the tongue thin (as Cillian O'Brien does) or you could cut it thick but thin it down at certain places on the tongue, namely the nodes where there is the least movement but the flexibility of that area would encourage stronger modes other than the fundamental.
Yes, there have to be some lessons to be learned from free-reed physics, even though as you say, drone reeds aren't quite free.
The question of fundamental vs. overtones is especially interesting. Just in my fumbling around, I've noticed that some drone reeds end up sounding "buzzier" or "beefier" (richer in overtones) than others.
I was already gravitating towards O'Brien's "less is more" attitude (re. tongue width) on purely practical grounds - most of my failed reeds have had wide & thick tongues. If narrower/thinner tongues yield a more interesting tone too, then all the better!
By the way, I'm having problems with the two different batches of drone reeds I thought were working. (Some days, I almost get nostalgic for my care-free days playing that simple, easy French horn...)
One set played great for about two hours after initial tweaking but now all three reeds want to clap shut. Adding curvature to the baritone & bass drones helps (though so far not persistently), but on the tenor reed it causes the pitch to devolve to a gurgle that sounds like the In-Sink-Erator (garbage-grinder) in my kitchen sink.
Removing/reducing the curve by sticking a sliver of cane under the middle of the tongue and pressing the tip down restores the nice D sound, but also the clamping-shut problem. Do I just need more finesse or is there something else I can do? There's already a big lump of window-putty on the tip of the tongue.
On my other set the drones still play perfectly. But two days ago the relative humidity here jumped way upwards. For some reason this made the pitch of my tenor & bass drones go very sharp: both of those tuning slides are now so far out they're in danger of dropping to the floor.
So, how do I correct (lower) the pitch on those reeds without screwing them up?
rorybbellows wrote:I was reading an article on how Kalimba players can tune the overtones of a note by filing away some metal in certain places on the prongs of the instrument.
The first question is , would the vibrational modes of a kalimba prong be the same as the tongue of a drone reed and if it is could the same techique be used to alter the tone of the drone reed /drone.
A kalimba is usually technically classed as an "idiophone", meaning the sound originates with direct striking or otherwise initiated oscillation of a solid. In this respect it is like a xylophone or bell.
The reed tongue does not play the same role in a drone. Our reeds are what are described as 'beating reeds', meaning that they 'beat' against the windway aperture and are totally closed for a significant part of the periodic oscillation's cycle. This is in contrast to the kalimba prong. It has been shown, though I don't recall by whom, that the input to the acoustic column produced by a beating reed is a narrow rectangular waveform, so narrow that it is very nearly an impulse function.
Modes of vibration of oscillators can and do occur simultaneously of course, as you infer with your diagram. The separation of an actual periodic motion into its component modes is described by the 'Fourier transform'; the Fourier transform of an 'impulse function' is the set of ALL modes, in equal intensity. What this means in the case of drone reeds is that a properly functioning and well made reed will actually feed all harmonics into the air column in equal intensity. (In practice there is an upper limit, because the reed's motion is not a perfect impulse, but the upper limit for cane quills seems to be at or above above the range of human hearing so we don't care.) But the harmonics will only end up being audible in the drone if the acoustic column can support them; those that the column does not support will fail to be reinforced by the standing wave and will thus be absent from the drone's sound.
Thus, for an ideal reed, i.e. one that is well constructed, leakproof, and well-behaved., the harmonic content of a drone is mostly a function of the bore. Note of course that the reed can and does have a 'biasing' effect which pulls the natural fundamental of the drone bore up or down; this and the change in the acoustic geometry as the tuning slide is moved in and out can indeed change the tone. In this case the tone is changing because either the fundamental pitch, or the acoustic column, or both, are also changing. An extreme change in the drone configuration, such as Geoff's 'overblown' weighted tongue, can also change the tone, probably by altering the 'edges' of the near-impulse function, or perhaps the tongue is really only beating every other cycle of the fundamental (I don't know if this is actually literally possible, but it is inferred by some explanations of the overblown-reed-making process). Another case where the drone tongue will affect the tone is when softer or less stiff materials are used; it appears that they don't result in as 'sharp' an edge on the impulse function, meaning that they are not opening and shutting as instantly. This results in a loss of harmonic content which can be readily observed in side-by-side comparison. Doubtless there are some similar divergences from the 'ideal impulse function' behavior that can account for things like the tonal variation attributed to other tongue materials such as elder, etc., or perhaps these are produced by differences in the inner geometry of the reed quill, which after all is the first part of the acoustic column.
Tell us something.: Playing Scottish and Irish music in California for 45 years. These days many discussions are migrating to Facebook but I prefer the online chat forum format.
IME, there are surprisingly few pipers and even pipe makers that prioritize absolute steadiness in drones. It appears that most have never experienced it and thusly don't know that it's even possible to have zero pitch drift at anything close to playing pressure. I feel that it is critical to have absolutely steady drones as a basis for playing in tune. Geoff's suggestions of arching the tongue is a critical step that seems to be missing from the understanding of many, who instead add weight to the end of the tongue, as Mr. Gumby mentioned, which will help it to not clap shut and lower the pitch, but will make the pitch go sharp with increased pressure. On rare occasions where the pitch goes flat with increased pressure, adding weight can be admissible but I prefer to move the bridle down instead, lengthening the tongue, which has a similar effect. Placing a hair under the tongue is never as effective as arching and will make it leaky, unsteady, and take too much air. It is also common for bridles to be not snug enough. There is almost no chance of steadiness if the bridle is even slightly loose. Rubber bands are virtually useless as bridles for this reason.
Steadiness is almost always accompanied by "double toning" where the resonance jumps up from a "looser", lower resonance to a steadier one when moving from a very low pressure into a more typical, higher playing pressure. If the drone doesn't exhibit double toning, then it is likely not even close to being steady.
IME, it is advisable to start with the assumption of dead steady pitch as the first order of business. When helping pipers adjust their drones, I almost always find weight on the end of the tongue, and it virtually always needs to be removed to achieve steadiness. If the pitch is rising with increased pressure, remove any wax on the tongue first. If it claps shut, arch the tongue. Be sure to pull the slide out to compensate for overall pitch. If the pitch still rises with pressure, move the bridle up, shortening the tongue. This will, of course, raise the overall pitch and possibly clap it shut as well, at which point you will need to arch it further. As the drone slide moves out, this will also add more back pressure which will contribute to steadying the pitch, assuming the problem is rising pitch which increased pressure. As the bridle gets raised and the slide gets extended, at a certain point, the drone may start jumping the octave. If this happens, you must back off the bridle a touch and push the slide in slightly.
It is quite common to run out of slide before one reaches steadiness at the proper pitch. IME, due to the lack of understanding about the steadiness issue, even among pipe makers, many drones are not made in such a way for it to be even possible for them to play steadily at proper pitch. Because of the much greater length needed for the bass drone, one can often run out of length if the priority is steadiness. I have often run into bass drones that play in E with the slide all the way out by the time I get it steady. Obviously, attempting to make a longer reed, etc... to get the pitch down is the first order of business at this point, but it is often necessary to make some sort of at least temporary adjustment to the drone itself, either by adding length or sleeving the bore with tubing. It is best to have a thorough understanding of drone acoustics before trying to optimize this sort of situation, but suffice to say that the bore should always step up in size slowly but surely from the reed end to the open end. A rough guide for appropriate bore size for a bass drone would be starting at 3/16" for the reed section, moving up to 7/32" or 1/4" for the middle section, then up to 1/4" for the male slide section, all connected with U-bends of no larger ID than 1/4", followed by an end section of 5/16"-3/8" ID. If you are having trouble getting the bass drone steady and down to pitch, and your bores are not close to this guideline, you may well be advisable to sleeve the bores. If the bores seem optimal (not too big) and you are still have difficulty getting it down to pitch then you may need to add length to the end somehow. It is less common to run into trouble with the smaller drones but I have often seen designs with what I consider to be inappropriately large bores on the baritone and tenor drones as well. Length is usually not as much of an issue because of the ration of slide length to overall length.
IME, it is not necessarily appropriate to assume that the maker understands this issue. If they can demonstrate absolute steadiness at pitch and show that they know how to achieve that, then end of story; but I have found it to be strangely absent from most pipers' and makers' experience. When one considers the informality of the traditional context until relatively recently it is not as surprising as it might seem.
With all this in mind, I find it prudent to pursue steadiness first, closely followed by overall pitch, of course, followed by appropriate pressure/responsiveness, with preferences of tone and volume last.
With very low pressure they'll reluctantly hum a soft low D that holds for a little while even as I increase pressure, but never for long, and certainly not when I throw the drones on at normal chanter-playing pressure.
