WTT #1 - Windway shape

Whistle
1

In the absence of a forum for such, and given that I, at least, have a technical question or two that someone likely has an answer for, I am opening this new thread:

WINDWAY SHAPE
I’ve noticed that the Clarke whistle has a windway that is curved on top over a flat-topped fipple. The blade is a mere depression in the tin, and is not flat. All of the plastic heads I’ve seen, however, have a rectangular windway and a flat blade. In fact, most of the whistles I’ve seen have a flat-ish blade.

Other than manufacturing simplicity when working with a round tube, is there any known advantage or disadvantage to either of these configurations?
TIA,
Bill Whedon
(edit 1 to change Subject)


[ This Message was edited by: serpent on 2002-10-29 19:55 ]

2

In fact, most of the whistles I’ve seen have a flat-ish blade.

Alba whistles have a curved blade. Anyone else not doing a flat blade?

3

I don’t own an Alba, but the pix I’ve seen sure are pretty! To your knowledge, is the blade sharp? In the Clarke trad, the material is so thin that sharpening the blade would seem superfluous. OTOH, I do know that there is frequent talk about “tweaking” Clarkes, but I’ve not seen much of same about Alba. I was just wondering about how it affects the sound.
BW

4

Bill, it would seem that you haven’t checked out too many high-end whistles. Most of the whistles I own have curved blades. These have curved windways as opposed to the D-shape of Clarkes or the rectangular or elliptic of Gen-types. The metal ones (Burke, Silkstone, Sindt, etc.) have the blade turned down at an angle in the end of the piece of pipe. The wooden ones (Thin Weasel, Busman, Abell, etc.) have the blade filed/sanded/whatever in the wood. The blade surface makes a cylinder at an angle to the tube axis, or maybe a cone. The blade is straight if looked at from above but curved if looked at head on.

The Alba is unique AFAIK, in that the blade makes a plane relative to the axis of the tube. The blade is curved if you look from above or upstream. (Hope this makes sense.) The Alba is lovely and the blade simply adds to this.

Charlie

5

Right-o about my not having checked out many high-ends. There’s a considerable dearth of 'em around here, as well as a dearth of cash with which to buy 'em for study. :slight_smile:
Cheers, thanks!
Bill Whedon

6

On 2002-10-21 14:41, MandoPaul wrote:

Alba whistles have a curved blade. Anyone else not doing a flat blade?

The fact is that Alba whistles have a flat/curved blade.The reson is easy to see if you check out a Quena.
But there is all so a curved windway,go figure.
:roll:
Wizzy

7

From my recorder playing library, the reason most often cited for a curved windway and blade is to keep the stream of air concentric with the shape of the bore. Sorta makes sense to me. On a more practical level, on whistles like mine a curved windway and blade is vastly simpler to make. The floor of the windway conforms with the ID of the whistle tube, as does the bottom surface of the blade. Filing the top surface of the blade naturally creates a curved surface there too.

8

Weird. The Clarke trad has a blade that curves in the exact opposite of the internal tube curvature. I think it makes for a fair amount of chiff, but in a way that (to me) sounds pleasant. I’ve been experimenting with a similar blade profile, though not as pronounced as Clarke, and seem to be getting a clearer tone, still chiffy, but not quite as prominently so. Speculation?
Bill Whedon

9

Hey Bill

Here are a few random, not well-thought out observations about windway shape most of which could probably be convincingly refuted by any maker:

The first thing I do when I get a Clarke original with a D-shaped windway is squash it flat with my thumb. Generally this reduces the air requirements and helps focus the sound.

To my mind, whistles with flat rectangular airways sound most like whistles (Generation and its clones, Hohner, Overton and clones, Tully).

Whistles with curved windways tend in my limited experience to sound purer and therefore in my estimation less like whistles and more like that other unmentionable instrument (Burke, Susato, Swayne). Whether this is inherent in the windway shape I couldn’t say. Also I’m sure many people will disagree strongly with admittedly this half-baked theory of mine.

The two curved-windway whistles I’ve tried that buck this trend are the Reyburn high D and the Alba. Both achieve a whistle-like sound but at the cost of much higher air requirements.

The Sindt is somewhere in between - could maybe benefit from the airiness a flat windway (as well as a cross-fingered C-natural). The ramp on the Sindt is machined (milled?), by the way, not bent as someone suggested above.

Reyburn low whistles also buck the trend by having a flat windway and a woody (r…rish) sound.

Other observations from tweaking flat-windway whistles (i.e. Generations) by narrowing (reducing height of) the windway. This produces very interesting effects. The more you reduce the height, the greater the “back pressure” and the softer and sweeter the sound (to my ears). The windway needs to be blown clear more often, though.

As the backpressure rises, it becomes easier to get flat second-octave notes - i.e. the greater the backpressure the more assertively you need to blow the second octave to be in tune.

Comments, anyone?

On 2002-10-21 14:39, serpent wrote:
In the absence of a forum for such, and given that I, at least, have a technical question or two that someone likely has an answer for, I am opening this new thread:

WINDWAY SHAPE
I’ve noticed that the Clarke whistle has a windway that is curved on top over a flat-topped fipple. The blade is a mere depression in the tin, and is not flat. All of the plastic heads I’ve seen, however, have a rectangular windway and a flat blade. In fact, most of the whistles I’ve seen have a flat-ish blade.

Other than manufacturing simplicity when working with a round tube, is there any known advantage or disadvantage to either of these configurations?
TIA,
Bill Whedon

10

The two curved-windway whistles I’ve tried that buck this trend are the Reyburn high D and the Alba.

Other observations from tweaking flat-windway whistles (i.e. Generations) by narrowing (reducing height of) the windway. This produces very interesting effects.

Comments, anyone?

[quote]
On 2002-10-21 14:39, serpent wrote:
In the absence of a forum for such, and given that I, at least, have a technical question or two that someone likely has an answer for, I am opening this new thread:

WINDWAY SHAPE
All the Alba’s that have been made in the last six months, now have a longer wind way so that the back pressure is increased.
ie: if you make it longer its the same as making it smaller.
:roll:
Wizzy

11

Steve,I dont have anywhere near your range of experience with all the whistles you have mentioned but I think you are mostly correct.I dont entirely agree with your curved airway theory.I think that sound you are referring to has more to do with voicing but agree with you that susato is voiced to exhibit the sort of tone you are aluding to.Shortening the blade thus increasing window size brings this whistle closer to what many percieve as a true whistle sound. The Susato heads I,ve adapted to Gen bodys take on a surprisingly Gen-like tone,only louder. Mike

12

My whistles have both curved windway and curved blade. The block is also trimmed to start out wide and then goes to duct shape for a certain distance in order to laminate the airflow.

13

My understanding of the arching windway is this:

Whether the blade is flat or curved, having the windway arch upwards in a curve that narrows as it approaches the blade is one way to form a tapered windway, which will increase the resistance of the whistle and help stabilize pitch at different breath pressures.

Having a curved and tapered windway is considered a very desireable mark of quality in the world of (dare I say it?) recorders.

Best,

–James
http://www.flutesite.com

14

Copeland high D has a curved blade; so does a Susato.

'luck now,
brian_k.

15

Okay, then from what I’m seeing here, the Clarke is an anomaly in whistles? Truth to be told, I’ve never seen another exactly like 'em. Most inexpensive ones I own have a flat blade and a rectangular-ish airway.

I tried flattening the top of a Clarke C’s dome, and it made little change, other than a bit more chiff. Somebody’s just going to have to take the bull by the horns and do some wind-tunnel tests on these configurations, complete with coloured (preferably orange) smoke!
Cheers,
Bill Whedon

16

I wonder where Thomas-Hastay has been? I seem to remember him doing some smoke test? Or am I remember incorrectly.

Erik

17

On 2002-10-23 14:23, serpent wrote:
Okay, then from what I’m seeing here, the Clarke is an anomaly in whistles? Truth to be told, I’ve never seen another exactly like 'em. Most inexpensive ones I own have a flat blade and a rectangular-ish airway.

I tried flattening the top of a Clarke C’s dome, and it made little change, other than a bit more chiff. Somebody’s just going to have to take the bull by the horns and do some wind-tunnel tests on these configurations, complete with coloured (preferably orange) smoke!
Cheers,
Bill Whedon

Bill The problem of trying to get you head around whistles is that all most every thing you can change will efect the way it sounds,and the way it plays.
the size and shape of tube, clarks whistle
is taperd, Its possable to have a stopped whistle, that is the end of the pipe filled in or a hole in it smaller than the bore.
This will also change the back pressure,panpipes have no wind way but your mouth. The colum of air is excited by hitting the bottom of the tube and bouncing back up only to be hit by more wind.
:roll:
Wizzy

18

Wizzy quote:

“…panpipes have no wind way but your mouth. The colum of air is excited by hitting the bottom of the tube and bouncing back up only to be hit by more wind.”

Which is why it is important to when tuning your pipes sharper to add a material that doesn’t cause the air to be “perturbed”. We used to use popcorn but if the tube was too flat due to humidity changes (cannot just cur them shorter cuz then sometimes they would be too sharp, it’s a thin reed) it sounded like a baby rattle when you played or just wouldn’t sound. Use rice, Japanese sushi rice works well, just remember to remove it when done playing or… well…jsut trust me on this one.

Mark V.

19

[quote]
On 2002-10-24 10:05, markv wrote:

Which is why it is important to when tuning your pipes sharper to add a material that doesn’t cause the air to be “perturbed”.
Mark V.

So Mark.
What shape is best for the bottom of the tube, Flat or domed or coned?
Wizzy

20

Isn’t the air stream perturbed anyway? A rough calculation indicated that the air in the windway is turbulant (Reynolds no. > 2000), so the air stream in the windway is not laminar. As soon as it leaves the windway, the jet that forms is turbulent too, so the idea that the air stream somehow retains the shape of the windway is probably not the case. If I can figure out how, I’ll post a animated gif of the air stream exiting the windway, forming turbulant eddies and hitting the edge.