Just to clarify this: Even though people are using the term “chiff” when talking about extraneous noise present in the tone, as I understand “chiff” is more precisely the attack transient sound before a steady tone is reached. - So “notching or nicking” can smooth out or remove extraneous noise or “sizzle” , but I take it it is not used to influence attack transients? Acoustically it seems to mean (purely speculating here) that more turbulence is introduced to the air jet (or wind sheet). So I am surprised that it should result in less “sizzle”. Are there equivalents in whistle construction for this “notching”? I thought that the smoothing of edges around the window, especially the exit of the windway, will help suppress “sizzle”.
~Hans
Hans, I think Reg does mean chiff in the more precise sense of the attack transient at the onset of the note, and nicking is a way to reduce that. I gather that 19c/20c organists like Milhaud and Fauré came to regard chiff as undesirable, and many period organs were voiced (and baroque organs revoiced) this way. Now I think the trend has come full circle, and the joys of chiff are once again in vogue.
I’m sorry, I probably wasn’t very clear in the explanation. It is kind of interesting to explain what I literally give no thought to anymore. Such is the result of many years of staring pipes in their faces!
The nicks do a couple of things. They not only control the “sizzle” in the sustained tone, but will attenuate the chiff in the attack. I guess I am more likely to refer to attack as speech, and chiff as articulation, at least when working with metal pipes. Chiff makes me thinks of wood pipes… anyway. When an organ pipe is new - and this would apply to whistles also, though probably not in every construction type or material - all of the edges are sharp. The foot, prior to the languid being attached, is planed on a machine that looks much like a meat slicer, so it is square and clean. then the languid it soldered on. The leading edge of the languid has on it a bevel - standard issue is 60 degrees or so (that’s yet another topic…) that has been planed by hand and is also sharp. Prior to soldering, the languid is positioned on the foot so that the flue, or windway meets whatever specs the pipemaker wants. If the windpressure of the organ where it will live is low, then the flues tend to be tight, sometimes VERY tight. I’ve often said that some low pressure pipes appear to have flues to tight that you couldn’t put a cigarette paper in them, in fact. maybe a bit of an exaggeration, but it’s all relative. If the pressure is high, then the flue must be wider for the pipe to speak properly.
When the air enters the toe of the pipe, which can be opened or closed accordingly according to the voicer’s needs, it exits via the flue and sets the column of air in the body in motion. Since the surfaces it passes - the inside of the lower lip and the languid edge- are very sharp, the “sizzle” occurs naturally in the sustained tone due to tiny eddies in the wind I would imagine, and chiff, or articulation occurs at the attack as a result. Nicking creates its own interruption in the eddies, but doesn’t create more noise, but will gently smooth the attack and sustained tone - if you keep nicking and don’t stop, and they get more numerous and deeper, then all the articulation will vanish, along with it any character the tone may have had to begin with.
There are standards of scaling (diameter/note ratios, basically) that apply to building organ pipes. The tonal designer, tonal director of the organ company or whoever, “scales” the organ relative to his/her “feel” of the room in which it will live based on experience and skill. In essence if the organ has 6,000 pipes, the person who scaled the organ, in one form or another, determined the pressure, scales, pipe specifications (material, mouth width, etc.) and knows the diameter of every pipe in the organ, or at least should!
Whistles are constructed with the languid as an integrated part of the block, and therefore the dynamics, as I see it, are much different. The machined and intentionally sharp edges don’t exist, and that’s surely got something to do with attack and sustained transient sounds and speech characteristics. Mouth width also comes into play, a narrower mouth is less likely to “chiff” - and O’Riordan whistle for instance - and a wider mouth is more likely to chiff, a good example off hand might be Grinter. The ones I owned had wider mouths. The same is true of pipework, generally.
The mystery of the whistle, based on my world, is that the “scale” changes with each note, though nothing else does except the pressure, which happens instinctively, I suppose. In other words, the body is one ratio when playing with all the holes covered, and as you go up, by the time you get to the second B (on a D whistle) proportionally the scale as I think of it is enormous, the mouth width off the charts and yet, it just sings way! It is truly a little instrument that amazes me every time I play it, and my hat is off to the whistlemakers for the skill it takes to execute the job!
Reg
Thanks, Reg, for your kindness to give us such long detailed explanations!
Fascinating! Now I want to watch an organ voicer at work!
Some high quality recorders and some whistles have a curved windway, and a curved sound edge (Susato and Burke whistles spring to mind as examples). I associate that construction with a cleaner tone. Do some organ pipes employ curved lips, or are they always straight-edged?
~Hans
In my experience , I’ve not worked with pipes with a curved lower lip which would result in a D shaped windway - though some whistles are like that. You do occasionally see pipes that don’t have a “flattening” that is, the flat upper lip like many whistles, as opposed to a whistle like Copeland or Burke which don’t flatten the body tube at the mouth.
If you’ve ever seen a high pressure steam whistle, they often utilize the entire body as the upper lip, being supported by a rod in the middle, and the windway is a complete circle.Subtlety isn’t likely the goal in such a case, however! Basically, wider mouths and higher cut-ups equal greater power, and vice versa, though not always as narrow-mouthed whistles aren’t necessarily mild nor cut up particularly high… Did that help?
I hope this rambling is helpful. Though I’ve played the whistle in church a time or two, I play only for my own enjoyment, and I couldn’t memorize enough tunes to make myself useful at a session if my life depended on it! And I have learned that you don’t want to be there with a music stand in front of you… so - i’m out! 
I’ve bought, sold and traded a lot of whistles, inexpensive and not so inexpensive in the past 2 1/2 years that I’ve been whistling and a member here, and I have to say it’s been the time of my life! This forum is invaluable to me for many reasons, is quite friendly and helpful - and like any family or community, they have the potential of becoming just as dysfunctional and self-destructive - so, hats off to Dale and his trusty cohorts. I’m grateful that I have something to contribute in ‘repayment’ for the literally countless hours that I and so many others spend here. And my hope is that what I write makes sense!
Reg
Well, I for one found you contribution interesting and helpful. I did come away with the idea that there is little science to this… why cant we computer model such a ‘simple’ system, when we can model the climate (sort of). Perhaps, on second thoughts, some things are best left as arts. I share your sentiments about this forum, and look forward to the day when I can contribute something worthwhile.
As an aside: the 5mm thick slice I cut off the top of v0.02 works better at strengthening the low notes than the now 13mm high v0.02. Isn’t that just the way life goes? v0.01 is 8mm high and better than either, so another slice coming off v0.02 tonight…
Chaos. http://en.wikipedia.org/wiki/Chaos_theory
Same with the weather. Itsy-bitsy changes in the “simple” thing we built yield huge changes in the behavior of the system it produces. Changes so small they are hard to measure with the best of gear. The only reason they get the weather as right as they do is they can see what’s heading this way.
This “Reflector” device Was first suggested by Arnold Dolmetsch (based on organ pipes) to improve the intonation of Duct-Flutes. The Main reason is Increased Chimney Height. This works by increasing acoustic coupling through isolation. The Duct-Flute airstream is isolated between the 2 “ears” and does not need to displace so much “inert air” at the sides of the labium ramp, saving energy. This leads to faster response time and greater initial acoustic energy below the window as well.
It takes more energy to sustain low frequency oscillations than high frequency oscillations and this is the reason the lower notes are much improved.
Thanks for that, Thomas-Hastay. I like that explanation a lot because I can understand it.
One question though - you say that low frequency waves take more energy to maintain. This is despite them containing less energy than high frequency waves? I would not have guessed that.
I believe they call that a “Van Gogh.” rimshot
I’m here all week, folks!
TGIF? 
DrPhill;
Frequency is independant of amplitude. Frequency is the number of cycles per second while Amplitude is the amount of energy contained in the soundwave.
All of us “Old Navy Sailors” know that low frequency Fog Horns have been used instead of high pitched whistles for hundreds of years because they are more effective at greater distances.
Yes, ask any elephant.
The idea of using a wind wall (or ears and beard using the organ pipe lingo) is a good one. However, perhaps a simpler approach to adding a wall would be to use a thicker walled tube for the head. This would offer the same thing, as the thicker wall would create a well around the window which would achieve the same thing.
Pvc tubing is available in thicker walled material.
Ronaldo
Doh 
I was confusing sound with with em-radiation where higher frequency is is higher energy.