Polishing the inside of a whistle

[anon81352336]

I saw a film about Henry Willis Ltd who are a famous organ builder.
It showed how the pipes were made and voiced.
One of the interesting points was that they polish the inside of the pipe as they believe this reduces turbulence.


Not sure I want to polish the inside of my whistle but its an interesting point so I thought I would throw it into the mix.

[Whistling_Archer]

The shakuhachi folk are totally into a extremely polished bore, I dont think it would help me any, but it is interesting.

[highwood]

I’m not sure if there is much difference between a reasonably smooth surface and a polished one (probably worth checking) but I can tell you that if you were to get too enthusiastic with the polishing you could change the tuning of the whistle.

[Impempe]

@GordonH

I saw a film about Henry Willis Ltd who are a famous organ builder.
It showed how the pipes were made and voiced.
One of the interesting points was that they polish the inside of the pipe as they believe this reduces turbulence.


Not sure I want to polish the inside of my whistle but its an interesting point so I thought I would throw it into the mix.

Also bagpipe (GHB) drones need a very smooth and straight bore for the best results. The didgeridoo on the other hand needs a very turbulent bore to maximise the overtones etc. These are basically all using a single note through the bore whereas the whistle bore has a few more notes than one. I suspect that the fingers covering the holes will cause more issues than a tarnished bore - my opinion is that it is a non-issue.

[chris_coreline]

@Impempe

Also bagpipe (GHB) drones need a very smooth and straight bore for the best results. The didgeridoo on the other hand needs a very turbulent bore to maximise the overtones etc. These are basically all using a single note through the bore whereas the whistle bore has a few more notes than one. I suspect that the fingers covering the holes will cause more issues than a tarnished bore - my opinion is that it is a non-issue.

so… hypothetically if somone makes a whistle with a terbulant bore it will add overtones to the note? Not to directaly equate whistle and didg, but they are vaguly based on the ‘big resonating tube’ school of instrumnets.
correct me if im wrong…
make it if im right

[MarcusR]

@chris_coreline

@Impempe

… a very turbulent bore to maximise the overtones etc …

so… hypothetically if somone makes a whistle with a terbulant bore it will add overtones to the note?

I don’t see how overtones/harmonics could be generated within the bore itself? A non smooth bore surface would instead lead to increased attenuation which is frequency dependant and will reduce the amount of higher harmonics. So if you want to preserve the overtones you have generated the bore should be like a mirror

/M

[ctilbury]

@MarcusR

@chris_coreline

@Impempe

… a very turbulent bore to maximise the overtones etc …

so… hypothetically if somone makes a whistle with a terbulant bore it will add overtones to the note?

I don’t see how overtones/harmonics could be generated within the bore itself? A non smooth bore surface would instead lead to increased attenuation which is frequency dependant and will reduce the amount of higher harmonics. So if you want to preserve the overtones you have generated the bore should be like a mirror

/M

It seems to me that a rough bore makes a less pure tone. Say a bamboo tube versus a brass one. Imagine a pond with nothing floating in it the ripples spread evenly. If there is a boat in it, then the ripples reflect off it. Same with the bore.

[MTGuru]

Just anecdotally … Whistles can accumulate quite a bit of fuzz and minor corrosion inside the bore between cleanings. And my impression is that the effect on the overall tone seems negligible.

I suspect this is a case where whatever small effect there might be is overwhelmed by other primary factors of fipple geometry and tonehole placement.

But maybe I should run some Scotch Brite through a dirty one and listen carefully for any difference. Not exactly polishing the bore, I know, but I’d think the effect should be in the same direction.

[brewerpaul]

I haven’t noticed a huge difference one way or the other. Some of the woods I use bore out to a very smooth surfaces, others have a slightly rough one. Doesn’t seem to matter much, although on general principles I sand the rougher bores a bit (but not enough to significantly change the dimensions)

[Tommy]

Here is more discussion on the same topic. https://forums.chiffandfipple.com/t/experiment-rough-bore-v-smooth-bore/26712/1

[ctilbury]

I wonder if you could tell any difference using a spectrum analyser?

[hoopy_mike]

Something I’ve been meaning to do for a while is to take a whistle and give it a nano-coating of gold on the inside to see if it makes a difference…

[sackbut]

My home-made low G was made from copper pipe salvaged from my brother-in-law’s skip after his loft conversion.

It had a very velvety tone, and also a fair amount of black deposit on the inside of the pipe.

Some time later I cleaned inside the pipe, and - no surprise - the tone became rather clearer and less velvety.
Not necessarily worse, but definitely different. No difference to the pitch.

[david_h]

I think I vaguely remember reading something, probably here, about roughing the bores of baroque traversos for better tone.

[hoopy_mike]

@sackbut

My home-made low G was made from copper pipe salvaged from my brother-in-law’s skip after his loft conversion.

It had a very velvety tone, and also a fair amount of black deposit on the inside of the pipe.

Some time later I cleaned inside the pipe, and - no surprise - the tone became rather clearer and less velvety.
Not necessarily worse, but definitely different. No difference to the pitch.

I’m struggling to make a fipple / head for a low C out of some 22mm copper pipe - any tips would be most welcome!

[MTGuru]

@ctilbury

I wonder if you could tell any difference using a spectrum analyser?

A good question. This is one of those urban legend issues, like the effect of material on tone, where I’d like to see some empirical evidence one way or the other. Where are the Mythbusters when you need them?

[hoopy_mike]

Well, a colleague made a couple of double skinned flutes out of carbon fibre. One had a foam core, so the material was the same, but the stiffness varied. There was no significant difference in tone (I think he did some spectrum analysis).

I’d like to try something similar with whistles, coating the inner surface and so on, but it’s so hard to produce any definitive results. Maybe I’ll convince a student into doing some expts this year…

[MarcusR]

@hoopy mike

Well, a colleague made a couple of double skinned flutes out of carbon fibre. One had a foam core, so the material was the same, but the stiffness varied. There was no significant difference in tone (I think he did some spectrum analysis).

If you by “spectrum analysis” mean to display a recorded signal in frequency domain after a FFT and compare magnitudes I doubt that you will be able to make any valid conclusions regarding the effect of the two bore surfaces.

@hoopy mike

I’d like to try something similar with whistles, coating the inner surface and so on, but it’s so hard to produce any definitive results. Maybe I’ll convince a student into doing some expts this year…

That should be a fun and very interesting project. But instead of spectrum analysis you would be far better of using impedance measurements or acoustic pulse reflectometry.
Just my 1/50th of a dollar

/M

[ctilbury]

I don’t know what reflectometry is. I was thinking that you would analyse to find if the body with the rough interior has more complexity than one with a smooth interior.

Another interesting question (to me) is whether the smoothness of the bore has an effect on the tuning of the instrument. I suspect that a rough bore would be sharper than a smooth bore with the same size parameters.

edit: added (disclaimer)…