SO, what is it about the low D whistle (mines a tuneable dixon), acoustically, that makes intonation widely ‘impure’ between octaves? Even with airflow (velocity) adjustment, I can t seem to get the upper 8ve notes in tune with the lower ones. This is correctable on every other whistle I own with embrochure/airflow/angle adjustment.. Why is a tenor recorder not problematic in this respect? Is this trait endemic to the low D species, or just this make & model?
The issue is common but not endemic to the breed. It is an issue that results in different design compromises by different makers. What you are likely bearing witness to is the fact that a cylindrical bore whistle will exhibit a flat upper second octave. It is a matter of physics. The same issue is present in high whistles but it becomes increasingly more noticeable in the larger whistles. There are methods that can correct this in design and construction but not all whistle makers will go to the effort of making these corrections. In some cases the correction requires more complexity in the building process which adds to time and costs. These types of corrections might include a constriction in the bore at the upper end of the tube. You could also add a choke at the bottom of the tube. But other methods are also used. The Dixon low whistles have gone through several improvements/redesigns over the years (as evidenced by the many Dixons I have owned). But the issue, while less prominent in current whistles, is still there. I actually think the current Dixon whistles are fairly good, especially when compared to some ten year old Dixons. The tuning slide on the Dixons used to be a real prominent problem.
What you can do to help is to tune the instrument to start with to a note besides the bell note or its octave. Tune to an A in the first octave. The G note is not a bad choice either. Check the tuning of the A’s in both octaves then. The difference should be less than if you tuned to D to start things. This helps reduce how hard you have to blow to bring the high A and B into line. Then you use your breath skills to keep things as close as you can make them. The bottom D may suffer a bit or have to be blown soft which might not be the best solution on some whistles. The second octae D should be close. It is worth the experiment to try it.
The tenor recorder (and it’s siblings Nino, Soprani and Alto) have better breeding in their bores. The typical baroque recorder bore is designed to help correct the octave spread. They also incorporate a pinch hole that helps generate the high notes a little easier.
Hope that helps.
Feadoggie
Hi CHasR
You don’t tell us what model Dixon you have. I only have 2 Dixon low D’s (The old DX003 and the newer TB003). These have been tweaked to be more air efficient and slightly increase the volumn. I have no problems with these whistles regarding tuning into the 2nd octave although breath control on the second octave E and F# is critical and if one overblows these notes go sharp. The G , A and B are very slighty flat, C and C# are almost spot and D is very slighty sharp according to my Crafter elctronic tuner. As I play with a Fiddle and Harp player these whistles are set to 441HZ.
When playing in the small sessions that I attend the very slight variance in tuning does not notice too much.
No doubt other more knowledgable forum members will be along later with helpful advise.
Ian
thanks. Do you have a suggestion for material ? something adjustable i presume. beeswax was my first thought, maybe tissue & tape?
yes- doing this, but D to d is far closer than either g to g’ or a to a’.
I will apply some reasonable intervention! Thanks 
Let’s talk about some things first. Ian Parfitt is right to ask about which Dixon you are playing and with which you are experiencing the issue.
Keep in mind I am not dissing Tony Dixon in any way here. I think he makes the best product he can and has always offered it at a reasonable price. I like and frequently recommend his whistles. i have owned quite a few of them myself.
Dixon makes a lot of different low D models - all polymer, polymer and aluminum, all delrin, etc. So let’s not be talking apples and oranges here. But if we just describe the all polymer models we have the following.
The newest Dixon low D design is the TB003, as Ian Parfitt has mentioned, which has a tapered or conical bore. That is the best solution to solving the issue. I’d assume that is not what you are playing.
The predecessor low D had a cylindrical bore. As I said, it went through some changes over time. The earliest ones had the tuning slide socket made into the body. The Head slid into that. In that arrangement, unless you had the head pushed all the way into the socket, tuning usually left a bore expansion in a most unfortunate spot. It really messed with the tuning overall.
The second version of which I am aware used a short piece of tube at the bottom of the socket which reduced the size of the expansion. It helped quite a bit. The unfortunate part of that change in design was that heads made for the earlier design were too long for the new bodies. Some players would try to mix and match old heads and newer bodies and it sometimes resulted in unusual tuning problems. Worse yet, at least one retailer of Dixons stocked heads and bodies separately. They sold a bunch of mismatched parts. It took them time to figure out what had changed.
The more recent models reversed the design of the socket so that the head has the socket sleeve built into it. This design moves the bore expansion well up the whistle bore to a point where it causes less of an impact on overall tuning. Good move on Dixon’s part. But the octaves may still be a tad flat but not so much that many players would complain.
So what model have you got in your hands? That could tell us what you are up against to start.
Then consider that tuning is a system issue. It’s like that old balloon analogy. Partially fill up a balloon with air an it is round. Push a finger into it at one point and the balloon expands outward somewhere else on the surface. So making changes in one area on the whistle to address one problem can effect other things. But if you want to experiment with the bore a bit you can use rolled card stock or other material (thin, flexible plastic sheet) that can be rolled round and taped to hold its shape to try a few things. These would be entirely reversible experiments.
For the head constriction you can roll a tube of material so that the outside diameter matches the inside diameter of the head tube. You want maybe a two to three inch long tube as the result. It should be enough material to reduce the bore by about 15% not much more. Place the tube in the head below the blade so that the blade to windway geometry is not obstructed in any way. Try to center the tube at about 1/5th of the total sounding length. See what happens. Move it around to see if and how much it changes things. Ideally you would like the inside ends of the insert to be tapered to meet the whistle 's normal bore - buy hey, we’re experimenting here.
For the choke you do essentially the same thing at the bottom of the body tube. The choke can be shorter, say an inch and a half. It’s meant to help maintain pressure in the tube as you play, but not as well as a tapered body tube does though. It also changes the virtual length of the tube, that effects tuning - that old balloon analogy is at play again.
Beeswax is not a bad material to use for some experiments. A word of caution on Dixons though. The head tubes and the bodies on the all polymer whistle are made of a polymer that is fairly sensitive to temperature. Working beeswax can involve heating the material place it, to shape it or to remove it. Dixon plastics can warp and change shape at fairly low temperatures. I used to buy warped Dixons off of a retailer that came around to local festivals. They probably warped from sitting in hot festival tents all day. I would warm the tubes and roll them back into shape fairly easily. But you do not want to use heat around the voicing window in any way and change the geometry of the noise making parts. That might be harder to repair.
Anyway, have fun. Worst case, there are a lot of well designed and made low D’s out there that will not exhibit the same problem.
Feadoggie
Has anyone had this problem with the Susato low D?
I didn’t. The Susato low whistles I’ve owned, all Kildares, were all pretty well tuned. You just had to supply the right amount of air. Being fairly free blowing there is some range in the pitch of each note, which I like, but the top end was not noticably flat to me. The inner bore of the Susato bodies is tapered just enough to facilitate their release from molds. That is not nearly as much taper as most designers would use to align the octaves but it doesn’t hurt and may be a little help. They are pretty good whistles.
Feadoggie
this one.
http://www.millersmusic.co.uk/images/medium/whistles/dixon_gr2354_whistle_MED.jpg
dont know the model bought it 2ndhand. A tampon in the bell (sorry, using piper terms for brevity) solves issues between low & high g, a, & b
but F# remains particularly odious in its octave to octave intonation.
Sugestions are welcome !:party:
btw Im not griping about the product— no one need get upset. 
Hi again ChasR
The model in the picture looks like a DX102. I have not heard any adverse comments regarding these. However I did have a late model DX003 that was flat on all notes and no matter how I adjusted the breath the whistle was just flat.
I contacted Tony Dixon Music (http://www.tonydixonmusic.co.uk) and told them what the problem was. They asked that I post the whistle to them so that they could test it. Fortunately I live in the UK so postal charges are not an issue.
The upshot being that after several emails and about ten days later a new TB003 arrived free of charge.
You may wish to contact Tony at the above email address to see what he says. He is very busy although very helpful when he is therel. If he is not available one of his staff (also extremely helpful) may be able to help.
Ian
First I wonder about the precise nature of this impurity. I’m guessing that the 2nd octave is flat?
Thing is, Low D makers have a variety of approaches to the tuning of the octaves. Any approach with which it is possible to blow the octaves into tune is acceptable, I suppose… just a matter of differing styles.
When I started playing all there were were Generations and they had a flat 2nd octave so that to play them in tune you had to blow the low octave at less than its possible maximum and strongly blow the upper octave. I guess we all took it for granted and many Low Ds are likewise made like that, the Dixon conical Low D I have, and every Overton Low D I’ve had.
The other extreme are all of the half-dozen MK Low Ds I’ve owned, which have the sharpest 2nd octave I’ve encountered, meaning that to play the octaves in tune you must blow the low octave nearly to the point of breaking and rather underblow the 2nd octave. (This has the advantage of evening out the volume differential inherent in all Low Ds.)
In the middle are the Reyburns I’ve tried. These have, in my opinion, the best-placed tuning of the octaves.
Any of the above can easily be blown into tune by the player. They’re just different.
BTW Overtons, with a flat 2nd octave, and MKs, with a sharp 2nd octave, both have cylindrical bores, so having a cylindrical bore does not necessarily mean a flat 2nd octave.
I don’t find any intonation problems with my Overton/Goldies or my MK, they need a slightly different approach but it’s up to the player to play them in tune. If you play the cheaper machine finished, rather than hand tuned, instruments there are always likely to be tuning issues to some extent.
Playing around with whistle optimization software, I compared cylindrical and conical bores. I varied hole size, hole position, and amount of taper, optimizing strictly for tuning across two octaves. For one hypothetical whistle head, the conical bore design did show more uniform tuning across the two octaves than the cylindrical bore design, but only by about 5 or 10 cents. For the high C#, the model predicted 30 cents flat for the cylindrical bore design, and 13 cents flat for the conical.
Results will be different in real life, but this gives an idea what a conical bore can and can’t buy you in terms of tuning.
Edit: The conical bore design ended up with holes about 20% smaller than the cylindrical design, but they were in virtually the same places.
On a Goldie any note has about 40 cents come and go depending on how hard you blow it so I don’t see how these sort of tests have much relevance. If it’s a decent instrument (many makes aren’t) then it’s the player that makes it either in tune or otherwise.
Yes, on most whistles any given note can be blown in tune with decent breath control. But … when playing, say, Kesh at speed, can you get the lower B, middle D, and upper E all in tune if the whistle demands that you back off on the B and lean in to the E? And what happens to the dynamic balance between the notes if you do manage to get them in tune? That’s where I, at least, want the whistle’s help to play in tune.
I think all you need is for the notes to be as easily playable in tune as you move up the scale. Every note has it’s own pressure and if playing a good whistle you get a first octave d flatter than the low D then probably your B is going to be slightly flat too. You can’t just play a whistle and expect to be in good tune without developing breath control. When you hear a good player playing in tune it’s generally not just because they have a whistle that’s more in tune than others, it’s just that they’ve learned how to control it. The octave to octave thing may be an issue with cheaper whistles but of the likes of a Goldie it’s almost certainly in the playing.
I don’t know about Goldies, but I’ve owned a number of Overton Low Ds (and other low keys) over the years and a noticeable feature is the wide range of pitch/pressure/volume possible in the 2nd octave.
It’s amazing, actually, how softly you can blow the 2nd octave and still have it stay up there, not drop down to the low octave. BUT when blowing the 2nd octave softly it’s extremely flat. To have the 2nd octave in tune with the low octave you must blow the 2nd octave quite strongly, at a rather higher pressure than is actually required to sound.
To crudely diagram the difference in octave tuning between these Low Ds, let’s say that the possible range of pressure in which a note will actually sound is 1-9. The pressure at which each octave has to be blown in this possible range of pressure/pitch (to be in tune) is in boldface.
low octave at bottom, 2nd octave on top.
Overton, Dixon
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MK
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Reyburn
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of course it’s a “feel thing” not a numerical thing, but this is a clear visual way to express how it feels for me to blow these back to back.
You can really hear the octave tuning discrepancy by sticking an MK and Overton in your mouth and blow the two simultaneously. Play low G, both whistles exactly in tune, then blow high G. Yowza! They’re probably a semitone apart.
Now, all of these whistles are equally “in tune”, they just require different blowing approaches by the player, which any good player will do without having to think about it.