As the title says, why? If someone made a metal whistle with the same specs as one of the high-end wooden whistles, would it be as loud?
good question. that hoover conical C that i just got is aluminum, but as thick walled as many wood whistles. it’s also fairly loud. i can see, maybe, why thicker walls on metal whistles might lend themselves to greater loudness, perhaps: wouldn’t the thicker walls be less likely to vibrate, so that they would absorb less of the energy.
is there a physicist in the house?
I’m not a physicist, but I play one on TV 
Actually, I’m an RF engineer with a background in musical acoustics so I can answer the question. In a nutshell there isn’t much real difference between wood and metal with the same bore.
For those who like gory details please read on…
Whistles, whether metal or wood, as vibrations (volume or loudness) becomes larger, more harmonics are created. For small vibrations the relationship between the displacement and restoring force are linear. As the amplitude of vibration increases the linear approximation is a poor representation of the curvilinear relation between force and displacement. The linear relationship is a differential equation that solves into a sine wave. As the relationship becomes non-linear, the solution becomes a distorted sine wave and levels off. The wave is still periodic so it has a harmonic spectrum, but more complicated waves have more power in the higher harmonics.
Instruments like the whistle and flute (open systems) have small dynamic ranges. Speaking in decibels, there is surprisingly little difference between materials as the volume is determined by the amount of air mass, wavelength and frequency ranges in the harmonics. It is the higher harmonics that make a high note sound louder, but in fact it is our ears begin more sensitive at these higher frequencies that make the note sound louder.
questions:
what’s an RF engineer? (sorry 
)
when you say “same bore” you mean “same inside diameter regardless of wall thickness,” right?
the reason i ask is because an anthropologist former colleague told me that metal vibrated more than wood or polymer, so that metal whistles should probably have thicker walls to get a purer sound. he always presented his views on all matters scientific in such a magisterial way that i was tremendously impressed with his opinions. however, experience led me to seek second opinions. 
RF = Radio Frequency. I design systems for passing RF energy (which becomes TV pictures, high speed internet and phone services) for a major cable company. Sorry if this is turning into an acoustics lesson, but I don’t know how else to explain it.
Actually if both the wood and metal have the same inner dimension (bore) and are smoothed to the same tolerance there is very little difference between them. If you measure the volume produced by both in decibels then you’ll probably see there is not much change.
What you will see is the frequency response of metal allows higher frequencies through than the wood. The reason is denser woods absorb them and have a higher impedance than metal. This gives the illusion that metal is louder than wood.
The issue here is the difference between volume and loudness. Two completely different issues. For any given material three conditions must be met:
- The tube must be rigid
- The interior surface must be smooth
- It must be impervious - leak-free and not spongy
Where wood, metal and plastic differ is #3. Metal and plastic resonant higher frequencies better than wood which makes them sound louder, but the air volume for a given bore produce the same volume.
We’ll avoid the issues of concave, convex, conical and cylindrical here
Most wooden whistles are pretty loud, but I think it’s due to design rather than to material. Paul Busman’s whistles are of moderate volume and extremely well balanced over the two octaves. I would say the same of my Abell. I would put these two at about the same level as a Burke WBB, possibly a little less loud than the AlPro. OTOH, my Thin Weasel (closely related to the Busman) is quite loud, and the Bleazey louder yet. The Bleazey may have the same volume as a Copeland, but is much more mellow.
finkelsj wrote:
We’ll avoid the issues of concave, convex, conical and cylindrical here
well, how 'bout just the last two, when you get a chance? i admit, most of this is over my head, but i’m glad to pick up even a little of it.
hey, chas, would you mind giving me a thumbnail account of your bleazy? i have it in my mind that if i get a small windfall i’ll look into bleazy C’s and Bb’s. i like my sweetheart laminate in D, my reyburn cpvc in D is extremely similar to the WW that you seem to like so well, and my hoover C and Bb aluminums are very nice, but, well, the bleazy’s do sound interesting. i know his are conical, and i’m wondering how they play.
Elendil wrote: “an anthropologist former colleague told me that metal vibrated more than wood or polymer, so that metal whistles should probably have thicker walls to get a purer sound. he always presented his views on all matters scientific in such a magisterial way that i was tremendously impressed with his opinions.”
Perhaps the anthropoligist meant that metal, as a denser material (by and large–there are, without doubt some woods that are harder than some metals), is a better conductor of sound than wood. Thus, if you put a steel bar under water and hit it with a hammer, the sound would, no doubt be louder and sharper to the human ear than the sound that would emanate from a piece of wood, such as oak, were it to be struck with the same hammer and with the same impact. This does not translate, however, into making the vibrating column of air inside a metal tube louder than the comparable vibrating column of air in a wooden tube (or, vice versa).
In any event, the above interpretation enables you to retain the magesterial view of the anthropologist in the face of the counter-intuitive (but aparently true) assertion that you can get the same sound out of a soda straw that you can get out of a metal tube of the same length and inside diameter. The reason most whistles are not made of straw, I would guess, is that it is hard to mount a pirated mouthpiece on a straw, straws don’t come in a wide variety of lengths or diameters, punching the holes would be a real ordeal, and they probably wouldn’t tolerate moisture very well. Otherwise…
For what it’s worth,
Tom D.
There may be a neglected parameter, in what I read above.
It is that some materials don’t have the same mechanical qualities in all directions.
Most polymers are like clay: mostly amorphous. Same for cast or extruded metal.
Wood has a fiber, which will propagate a vibration lengthwise, damp it crosswise.
I can distinctly hear a difference between extruded aluminium tube (amorphous) and the same tube drawn (oriented), more complex and louder with the same plastic head.
Copelands are made from drawn tube, and then they’re annealed, which will also tend to orient its crystalline structures lengthwise.
It may be akin to the reason that, for the same mass and sections of metal, a forged metal bar is both more flexible and resilient than the same one cast. Even concrete gets resistance from adequate vibrations through the steel rods.
If all the above has nothing to do with resonance, then I’d better start making clay or plaster whistles.
Hey–same bore, etc.–according to some theorists, a clay trumpet would sound the same as brass, wouldn’t it? :roll:
I think the difference is mainly in the voicing-- with little changes, you can make the same diameter, material etc whistle come out either louder or softer by altering the voicing. Mainly the dimensions of the window. Within limits, wider is louder, narrower is softer. This is nice since if a player wants a whistle for a particular purpose eg sessions as opposed to quiet solo playing, the whistlemaker can accomodate those wishes.
In theory there is no difference between “Theory” and “Practice”
But in practice, there is
Yes, this is what i have in mind: think of 3 loud whistles. Discard the Susato and the other 2 are probably wood, right? Think of 3 soft whistles, discard the Hoover PVC and the other 2 are probably metal.
But it seems logical that a metal whistle should be louder than wood, so the difference is in the voicing. Why is it that wooden whistle makers seem to voice their whistles louder? Is it perhaps because the wood gives a mellower sound and they can afford to be louder without being shrill?
g
I dunno about quiet, but I would certainly put Copeland among the three loudest, possibly THE loudest. I hear Serpent makes a metal whistle that will take paint off walls. ErikT and Overton/Goldie make pretty loud metal whistles, too.
I agree that wooden whistles may on average be louder than metal whistles are on average, but they’re also more expensive. Maybe the people who shell out 300 bucks for a Weasel (or Copeland) want to be heard, whereas the people who shell out 10 bucks for a Clarke don’t mind blending in. Not an assertion, just a possibility.
Blending in? No, i want to be heard! But i’ve never paid more than $100 for a whistle. Hmm, Copeland… isn’t this the one somebody was taking apart just recently in another thread? I should look into that.
This is the age-old question, what is the difference between loudness and volume. BrewerPaul has it right, the larger the bore, the more air, the greater the volume dB (decibels). The higher the harmonics, the louder the whistle sounds.
Sound level in dB is a physical quantity and may be measured objectively. Loudness is a perceived quantity and one can only obtain measurements of it by asking people questions about loudness or relative loudness. (Of course different people will give at least slightly different answers.) Relating the two is called psychophysics. Psychophysics experiments show that subjects report a doubling of loudness for each increase in sound level of approximately 10 dB, all else equal. So, roughly speaking, 50 dB is twice as loud as 40 dB, 60 dB is twice as loud as 50 dB, etc.
I don’t personally care what the whistle or flute is made of. I just enjoy the sound.
(Goes to check and finds out that they’re way, way, way out of his range. Oh well.)
Me neither, but a wooden instrument requires a lot more care, while metal or plastic you can pick up and play anytime. Plastic is the least affected by temperature changes.
You’re going to have to show me a double blind study on this one, Zub. I am skeptical.
As a maker who does just that, ie makes wooden and aluminium whistles to basically the same dimensions, here are a couple of observations.
Whistles do vary in volume, but the variation seems to have more to do with small dimensional differences in the windway and window/ramp area. If I had the appropriate apparatus, it would be interesting to look at the wave patterns of a large number of whistles, say 50, of each sort, and produce an ‘average wave pattern’ for each group. I think the amplitude (volume) for each group would be very close, but the most obvious difference would be in the shape of the wave. Even trying to produce ‘pure’ sounding whistles, there are obvious differences between the different materials. Trying to describe the difference is difficult, but would be much easier with a visual comparison of wave forms.
No prob’: a well-known manufacturer just switched from one to the other, and I had a chance to cross-test them just swapping tubes, everything else (=head, placement, size of holes) equal. Resonance superior with the drawn tube. Now some may point out it may be due to bore surface more than walls structure, but…
why do you use sterling silver, anyway?