R&D Report: Thread wrapping makes the flutes sound good

Irish Flute
1

You discover things when you build stuff, like pocket lent.

More important than the pocket lent, you discover how to make things better.

I’m in the process of trying to start a flute making buisness over here (That sounds like a lot more than I’m actually doing… I’m building flutes and trying to sell them, simple as that), and I’ve been doing some expiremtneing.

PVC flutes are really boring to look at. White tubes with holes on them. I do my best to make them look nice, but a white tube is still a white tube, even if it’s sanded, polished and beveled. Boring. I realize that PVC will never look as cool as exotic wood, or even normal wood, but I refuse to believe that PVC cannot look pretty.

So, I’ve been doing some thread wrapping on some of my flutes. It helps. They are still white tubes, but now they have some nice wrapping and all in nice colors and patterns.

Funny thing happens. I’m playing one of my flutes that I just finished wrapping, and then I play an identical flute that is plain. The wrapped flute has a stronger, more stable tone, and is rounder sounding at the same time. So I says to myself “Self, your probably going crazy, but you need to know if there is something to this…”

So I take two more identical flutes, wrap one, and leave the other. Same thing.

I don’t really understand what it’s all about, I am not some kind of physicisit, My education is in Bible.

This is my theory: The tension caused by the wrapping increases the rigitity on the inside the bore. This stablizes the wind tunnel, and causes fewer vibrations to be absorbed by flute body itself.

The effect seems most apparent when the thread wrapping is between the finger holes and the emboucher. I haven’t done enough expirmenting to be sure of this, but it makes sense, kinda like a boehm flute will sound better if you improve the material of the head joint.

That is my report.

2

That s very intresting.

3

My spelling is atrocious.

Apollogies.

sound it out.

4

Hello Ninja,

In Japan, they use for folk music (but also Kabuki theater and Nagauta music) a special type of little 7 hole flute, called shinobue.

Those flutes come in different form, wrapped or not:

Japanese flute players have the same theory about the influence of wrapping on sound. :slight_smile:

5

Interesting…

I’m turning Japanies! I think I’m turning Japanies, I really think so!

Here, I just uploaded a picture of me trying to make PVC look pretty.

6

That looks pretty cool.

7

From the photo it looks like the lapping is on the outside of the body?

A different situation to normal lapping on joints.

Kevin

8

Your wrapped flute does look pretty that way. The dark thread really stands out against the white PVC. The bottom end reminds me of fishnet stockings. :smiley:

Bob

9

COOL!

berti

10

Aaron Christianson: Maker of the sexiest PVC flutes in the world.

11

That is correct. I am either to stupid or too lazy to figure out how to make a jointed flute.

My flutes are one peice.

12

Could very well be. Or it could just be psychological. :smiley:

Either way, it’s an interesting experiment!

13

Hmmmm . . . wrapping adds extra material to the wall of the flute. Could it be that it thus changes the composition of the wall and therefore the resonating properties?

Whereas before you had a thin PVC wall, after wrapping you have a composite PVC/thread wall which is 1.5 to 2 times (?) as thick as plain PVC. The wall is therefore thicker and it’s not the same material.

14

Ok kids…here’s the deal…

If I were to do a complete solution for the open-ended flute (acoustic resonator) as opposed to the closed (both ends) which I’ve already done, then I would have to include the outside surface of the flute in the boundary conditions (ignoring the fingers for now) So the surface contours of the outside do make a difference…not as much as if the thread was on the inside…but a difference which will be greatest near the holes etc etc

15

Hi Jack, are you saying that you calculated the pressure standing wave in a tube, closed or open; then calculated the bulge in the wall. Lets say they bulge an amount (delta)r, radially. The (delta)r will be the product of the pressure at the wall times the elastic modulous, right. How much does this (delta)r change the frequency of the resonator? In addition the tube has a naturel “bulge” resonance frequency, probably way up there. Is this out of the hearing range? This will put sidebands on the air resonance, way out there, but it has to sap some of the low frequency stuff, right?

Please send me any of the arithmatic you have done.

Nelson

16

Nope, what I had done was a rigid wall calculation. Just did the acoustic case of three coupled partial differential equations rather than the electromagnetic two equation case.

But…that might be an interesting case…esp. if the wall was thin and had few internal losses (ie glass or something)…if you could get some resonances to line up as well…

I’ll get you the math from the wayback machine for what I did…

17

:astonished:

18

So I was right? it is a matter of tension and rigitity that makes the difference? More stable air colum?

19

Nope, its probably the slight change in airflow on the outside of the flute…

20

Uh… it works on the flutes that don’t have any wrapping near the finger holes, only up by the embouchure.

I’m gonna go back out on my limb and stick with the rigitity thing. the wrapping is very tight, and PVC is relativly flimsy, so I think it still stands to reason that…