Intonation on a homemade whistle

JohnPalmer · Post by **JohnPalmer** » Wed Feb 20, 2002 2:14 am

I have some questions about a whistle I made out of the gray PVC piping. It is a low Eb.

First of all, before I even drilled a hole, the octave Eb was sharper than the bell tone. (I have a strobe tuner)

Secondly, after drilling many tubes to fit the mouthpiece, I finally got all of the low register to be in tune. In fact, every note stopped the strobe in its tracks, but I can't say the same for the second octave. Up there, some of the notes are sharp, while others are flat.

Thirdly, I checked the hole diameters of my Burkes and my one and only Water Weasle, to find that they pretty much have only three sizes of holes at two each, yet my Dixon and Susato low D's have no pattern on the hole sizes or where they occur in order.

What I mostly want to know is, how do I get my upper octave in tune???

Thanks,
JP

Bryan S. Poe · Post by **Bryan S. Poe** » Wed Feb 20, 2002 2:06 pm

Hi Jon,

I am more of a flute maker than a whistlesmith, but a very useful resource for making all sorts of instruments (including whistles) can be found at the musical instrument makers forum (MIMF.com). Check it out, a forum regular named Daniel Bingamon may be able to help if you rtopic is not addressed somewhere in the MIMF library.

Best of Luck,
Bryan Poe

Messing · Post by **Messing** » Wed Feb 20, 2002 2:14 pm

Hello John,
I have a few homemade whistles here. What I would suggest is to move the holes down 4-6 mm. They may have to be slightly bigger but you should find the intonation in the second octave better. If the holes are too small for the tube it may well be in tune in the first octave but flat in the second. This will also make it slightly louder. Hope this helps.

Thomas-Hastay · Post by **Thomas-Hastay** » Wed Feb 20, 2002 6:13 pm

Dear John {sorry,couldn't resist

}

PVC tube is an "extruded" polymer and because of inconsistancies in the catalyst and uneven cooling,the tube's inner diameter can vary. The thickness can also vary. Both of these factors can affect the pitch of the toneholes.

If a particular tonehole plays a few cents flat in the second mode,sand the area around the tonehole's upper edge. In effect,this shortens the air column(sharper)and is easier to control than enlarging the hole size.

If the tonehole plays sharp in the second mode,use PVC cement to build up a "bead" around the upper edge of the tonehole. In effect,this lengthens the air column at the tonehole(flatter).

These modifications have to do with the "Tonehole Lattice Effect" and the "Frequency Cut-off Location" in the upper modes and will have little,if any,effect on the fundamental mode(within reason).

Final word: To quote Arthur H benade...

"The frequency of the lowest vibrational mode is determined jointly by the internal shape and the cubic volume of the cavity,while the frequncy ratios of the upper modes are determined by shape alone."

This means that a slightly conical(increasing or decreasing)bore will change the upper mode frequency spacing but will have little effect on the fundamental mode spacing.

Thomas Hastay.

JohnPalmer · Post by **JohnPalmer** » Thu Feb 21, 2002 12:14 am

Hey Thomas,

I hope you are impressed with this one! The quote you just gave me is from Arthur H. Benade's book, Horns, Strings and Harmony, from page 151, copyrighted 1960. (I was two when it was written.) Why are we reading such old books?

And let me give you another quote from his book, from the same page and chapter on whistles:

"By now you are wondering why I have spent so much time on silly little noisemakers..."

Maybe we should find out if Dr. Benade is still around, and then send him a CD of Joannie Madden!

Thanks,
John Palmer

Sorry about this edit. I spelled copyrighted rong.

[ This Message was edited by: JohnPalmer on 2002-02-21 01:17 ]