Didgeridoo Shape Examiner FAQ

Why do I get an error message when trying to install the most recent version?
Why is the application slow, even though I have 8 CPU cores and all are being used?
Can I specify a cone shape?
Why does the calculated fundamental frequency differ from the actual pitch by a halftone?
What data do I enter if the shape of my raw (wood) material does not allow circular cross-sections?
Can I calculate Y-shaped didgeridoos or similar branchings?
How can I increase the accuracy of the graphical input?
Why can't I paste numbers from the clipboard?
How does the knot didge, shown on the DSE main page, sound?
 
  DSE main page
 
Why do I get an error message when trying to install the most recent version?

Uninstall the previous version first, using the regular uninstall function in the Windows program overview. If something goes wrong, you can remove the DSE files and the corresponding subfolders manually. In Windows 7 (or later) you can find them in
C:\Users\YOURUSERNAME\AppData\Local\Apps\2.0\.
In Windows XP check
C:\Documents and Settings\YOURUSERNAME\Local Settings\Apps\2.0\.


Why is the application slow, even though I have 8 CPU cores and all are being used?

Check your power (saving) options. If you use a laptop, connecting the power adapter might help. Read the section "calculating time" in the DSE manual.


Can I specify a cone shape?

Yes and no. Conical segments are not supported. Though, you can generate short segments and use the linear shape smoothing to approximate a cone by small increments. The single segment remains cylindrical.


Why does the calculated fundamental frequency differ from the actual pitch by a halftone?

There are many influencing parameters for the sound. The didgeridoo calculator application only considers the most important ones. In case of sound deviations, these are the usual suspects:
Exactly matching a predefined geometry with hand-held tools is difficult. Often a little less or too much material is being removed or deep grooves are left in the surface. Single irregularities usually do not have an impact, but there can be many of them along a 2 m instrument and their sum might cause unexpected results. Using templates is advantageous.
The flow cross-section is not circular. Usually this is not a problem (cp. next question), but in case of irregular geometries it is more difficult to correctly define the equivalent diameter of a circle with the same cross-sectional area. The application assumes circles.
In case of flow paths with tight bends, e. g. 180° deflections in traveler didges, the effective oscillation-relevant length is smaller than the path along the geometric center line.
Elastic walls (PVC tube, vacuum cleaner hose) can have an unwanted damping effect. The software model does not consider the wall material. Hard walls are required to match the predicted frequency.
Small leakages (cracks or holes) can significantly change the sound or even render the instrument unusable, especially if they occur near the mouth piece.
The chosen temperature is unrealistic, e. g. 0 °C in summer or 40 °C in winter.
The required amount of air is usually small and the air which leaves the instrument is hardly above ambient temperature, especially in case of long didgeridoos. This means that the temperature and thus the sound velocity inside the instrument significantly correlates with the ambient temperature. A didge which has been made and "tuned" in summer at 30 °C will have a lower fundamental frequency when played outdoors in winter at ‑5 °C. Furthermore, the application assumes a uniform temperature and not a temperature distribution along the instrument.


What data do I enter if the shape of my raw (wood) material does not allow circular cross-sections?

Little deviations from the circular cross-section are no problem. You can assume an equivalent diameter D = √(A·4/π) where A is the measured cross-sectional area. A usual und quick way of determining irregular areas is to create a sketch on scale paper and to count the squares. In case of an ellipse use the geometric mean D = √(D1·D2) with D1 and D2 as minimum and maximum ellipse axis diameter.


Can I calculate Y-shaped didgeridoos or similar branchings?

The application considers one mouth piece and one opening. Though, the special case of a completely symmetrical "Y" can be calculated, i. e. from the branch point to the openings both pipes have to be identical with regard to diameter profile and length. As in the question before, use an equivalent diameter D = √(A·4/π) with A as the sum of the cross-sectional areas of both branches at the corresponding position.


How can I increase the accuracy of the graphical input?

Increase the size of the input window to have more pixels for length and/or diameter of the didgeridoo shape, thus increasing the resolution. If this is not sufficient, uncheck "Options - Graphics and table - Mirror at center line". Finally use the table for "fine-tuning".


Why can't I paste numbers from the clipboard?

If "Ctrl V" does not work, the clipboard contains invalid or too many characters or the number exceeds the defined parameter limit. Depending on the language / regional settings of your operating system the comma or the period is the decimal separator.


How does the knot didge, shown on the DSE main page, sound?

Not at all. Another reason to calculate didgeridoos in advance. It is made of fiber glass and epoxy resin, i. e. materials which are generally suitable for this purpose. But it became too long, too voluminous and it does not have any noticeable backpressure. You will feel dizzy after half a minute of feeding it with air without any result.