Re: Wood whistles
Posted: Sat May 06, 2023 7:21 pm
I don't think that physical resonances in say the flute or whistle tube (or in the solid-wood electric bass body) are likely to add much to the sound.
Firstly, there isn't much scope for exciting these resonance. If you have a whistle with removable head, you can try. Hold the body between finger and thumb about one fifth of the way from one end. Now, using a pencil or something similar tap the middle of the longer bit or the open end of the short bit. You'll hear the clunk of impact, but you should then hear the resonance of the tube acting as a glockenspiel bar. If you don't hear the resonance, move your grip up and down a bit and keep trying.
Now that you are an experienced glock player, you can try holding it closer to the end and repeat the tapping. By changing the nodal point you should be able to bring out a few different partials.
So, yes, we can excite an audible resonance in a metal tube, but we have to hit it with something fairly hard. Try hitting it with your breath.
But secondly, our way of holding the instruments will dampen out those resonances. Hold it say fingering any of the left hand holes and try tapping it again. Thud. We've damped the resonance by holding it not at a nodal point, but near the middle.
But that's not to say that the body can't have effect in other ways, ways we could call subtractive, rather than additive. A good example would be raised grain inside a wooden flute or whistle that needs its bore repolished. Play it, it sounds a bit dull and sullen. Re-polish it, and it perks up and thanks you. (I artificially raise the grain of the bore of my flutes and polish it off before oiling. Saves the owner having to send it back later!)
If the walls of a wooden flute or whistle are made too thin, you lose energy to them. I have a very thin-walled bamboo low G whistle that falls into this category. It weighs 42 grams! Or if the wood is too light and/or open-grained. This was the lesson from my Pine Prattens experiment.
As the walls get thicker, you are adding little cylinders of extra tubing at each of the finger holes, which can mess with the tuning and the responsiveness. Increasing the hole diameters and/or undercutting can reduce this, but not eliminate it. Again, a subtractive effect.
I'd agree that using different metals on Boehm flute heads seems unlikely to alter anything, although some whistle makers claim some metals sound better than others. But given the hand-dampening, I think we can rule out tubular resonance!
I have made wooden heads for Boehm flutes and heard a significant difference. But again, it's more likely to be subtractive than additive - I can't see the wood vibrating audibly when jammed in the end of a silver tube and pushed up against the lip! And it might just come down to the fact that excavating the shape you want from the solid is just easier than fabricating it from sheet metal.
I do stoutly maintain we can easily perceive the difference between flutes (and probably whistles) made from timbers that are too light and/or coarse. When coming up with a new model of flute, I've used pretty reasonable timbers for the prototypes (no point in using rubbish, as that could be misleading!). EG Australian Acacias and Eucalypts around the 1.0 gms/cc. And they sound and play OK. But it's not till I then make a version in Blackwood or Gidgee or Mopane that I really hear and feel the full potential. And yet these are only 20% or so denser. But perhaps we're sensitive to that last 20%?
And I will admit to being puzzled why going on to Delrin at 1.4 (ie 40% denser, as well as being finer, smoother and totally impervious to air) doesn't seem to bring further benefits. Maybe we had already got there?
Firstly, there isn't much scope for exciting these resonance. If you have a whistle with removable head, you can try. Hold the body between finger and thumb about one fifth of the way from one end. Now, using a pencil or something similar tap the middle of the longer bit or the open end of the short bit. You'll hear the clunk of impact, but you should then hear the resonance of the tube acting as a glockenspiel bar. If you don't hear the resonance, move your grip up and down a bit and keep trying.
Now that you are an experienced glock player, you can try holding it closer to the end and repeat the tapping. By changing the nodal point you should be able to bring out a few different partials.
So, yes, we can excite an audible resonance in a metal tube, but we have to hit it with something fairly hard. Try hitting it with your breath.
But secondly, our way of holding the instruments will dampen out those resonances. Hold it say fingering any of the left hand holes and try tapping it again. Thud. We've damped the resonance by holding it not at a nodal point, but near the middle.
But that's not to say that the body can't have effect in other ways, ways we could call subtractive, rather than additive. A good example would be raised grain inside a wooden flute or whistle that needs its bore repolished. Play it, it sounds a bit dull and sullen. Re-polish it, and it perks up and thanks you. (I artificially raise the grain of the bore of my flutes and polish it off before oiling. Saves the owner having to send it back later!)
If the walls of a wooden flute or whistle are made too thin, you lose energy to them. I have a very thin-walled bamboo low G whistle that falls into this category. It weighs 42 grams! Or if the wood is too light and/or open-grained. This was the lesson from my Pine Prattens experiment.
As the walls get thicker, you are adding little cylinders of extra tubing at each of the finger holes, which can mess with the tuning and the responsiveness. Increasing the hole diameters and/or undercutting can reduce this, but not eliminate it. Again, a subtractive effect.
I'd agree that using different metals on Boehm flute heads seems unlikely to alter anything, although some whistle makers claim some metals sound better than others. But given the hand-dampening, I think we can rule out tubular resonance!
I have made wooden heads for Boehm flutes and heard a significant difference. But again, it's more likely to be subtractive than additive - I can't see the wood vibrating audibly when jammed in the end of a silver tube and pushed up against the lip! And it might just come down to the fact that excavating the shape you want from the solid is just easier than fabricating it from sheet metal.
I do stoutly maintain we can easily perceive the difference between flutes (and probably whistles) made from timbers that are too light and/or coarse. When coming up with a new model of flute, I've used pretty reasonable timbers for the prototypes (no point in using rubbish, as that could be misleading!). EG Australian Acacias and Eucalypts around the 1.0 gms/cc. And they sound and play OK. But it's not till I then make a version in Blackwood or Gidgee or Mopane that I really hear and feel the full potential. And yet these are only 20% or so denser. But perhaps we're sensitive to that last 20%?
And I will admit to being puzzled why going on to Delrin at 1.4 (ie 40% denser, as well as being finer, smoother and totally impervious to air) doesn't seem to bring further benefits. Maybe we had already got there?