Just a sanity check (not for me, we know the answer to that ). Where does the sound come from a whistle? I am assuming that it comes from the highest open hole and the ‘fipple window’ in some ratio determined by acoustic geometries.
So D on a D whistle the sound comes from the end of the whistle and the window, for the B note the sound comes from the window and the A hole? Hmmmm, terminology problem - from the second-to-top hole.
The reason I ask is that if significant portions of the sound always come from the end of the pipe whatever the note, then the direction of the end of the whistle may influence overall volume. If this only applies to the bell note, an audience facing pipe end may not be as useful.
The great majority of the sound emanates from the window (and from the embouchure hole on transverse flutes), but some does come from the tone-holes, especially the highest open one, and also from the end. This is one reason why both flute and whistle are difficult to mic well to accurately reproduce their acoustic sound, which needs some space to merge and develop into what a listener hears, and is also part of why the player’s impression of his own sound is different from a listener’s. If one can record ambiently in a good acoustic there shouldn’t be a major problem in getting a realistic reproduction, but for gig sound system amplification where distant mic placement isn’t feasible, then it is much more difficult. I think most players end up accepting that their gig P.A. sound won’t be that close to their real sound and try to work out what sound they prefer in that context given the technical issues. For studio contexts where a natural acoustic is either unavailable or not desired, a close mic plus a boundary mic can work better than just the close mic, and for larger instruments like low whistle or concert flute, having a short range mic close to the window/embouchure and one with a wider range pick-up field aimed about 2/3 of the way down the tube in addition to a boundary mic is a fair way to collect a selection of sound impressions to combine into the mix. Sometimes when gigging I can do something similar for my larger toots by using the stand mic I need for playing my smaller whistles and piccolos mid-tube and my strap-on Microvox (too cumbersome on the smaller ones) at the head.
Of course, any fairly close miking of the tube also carries a risk of picking up finger slap, tube-boom and key rattle/slap noises which are not usually audible to listeners in a natural live acoustic.
The sound waves from a whistle radiate from the window and the open hole(s) equally. If you have all holes covered (bell note), you have equal sound radiation from the window and from the end of the tube. If one or more holes are open, not all of the end sound comes from the first/highest open hole, but some proportion will be radiated from the open holes further down, including the end of the tube. So half the power radiates from the window, the other half may be split amongst a number of open holes including the end, but the highest of these will carry the lion share (I don’t know the exact proportions, and it will depend on hole sizes).
Ok, thanks guys. As usual it is more complicated than I thought - but in some ways that is good news.
I was thinking about the geometry of the end of my bass A. I find that its size and the use of two thumbholes make it easier to play if I rest it against my leg, but that may muffle the sound some. I have been pondering two solutions to this:
Cut the end of the tube at some angel other than 90 degrees. A 45 degree end leaving the back longer would allow me to brace the back against a leg/chair/whatever, without covering the end hole.
Add a bend to the end of the whistle so that any sound emanating from there is directed forward towards the audience. This will allow me to brace and perhaps increase perceived volume.
I have no idea what either of these might do to calculation of hole placements. I suspect the first may have a nominal length half way between the shorter and longer tube lengths. The addition of a bend will be more complex, I suspect. In either case I would take the heuristic approach.
The application of these matters to recording whistles is one I had not considered, though. It might imply that a stereo mic should be used towards/away from the whistler rather than left/right.
another option is to use a longer tube, and add a seventh hole for the A bell note, or better add two extra holes, and tune these to get your bottom A. Then you can rest the whistle wherever you like, on the bottom.
you need to reprogram your calculator, say for an eight hole whistle:
1-1-2-2-1-2-2 semitone interval steps, with root (bell) at low low G:
G G# A B C# D E F# G#
With two holes open at the bottom you got hopefully enough venting, even if the tube end is blocked, because it rests on grass or something.
). Where does the sound come from a whistle? I am assuming that it comes from the highest open hole and the ‘fipple window’ in some ratio determined by acoustic geometries.
