The Supplementary Information Table - edwardkort/WWIDesigner GitHub Wiki
Introduction
The Supplementary Info tool generates a table of additional information calculated by the study model, to assist with evaluating instrument performance. You can use this tool with any study model. At present, the mathematical models used to calculate this information are speculative, so the numbers here should be used with caution.
Supplementary Information
To display the supplementary information:
- Select an instrument and a tuning in the Study panel.
- Select Tool-->Supplementary Info.
For the sample PVC whistle, the Supplementary Info tool produces the table below.
About the Supplementary Information
For each note in the tuning, the table shows some the quantities listed below. The NAF study model calculates these quantities at the predicted playing frequency; other study models calculate the quantities at the target frequency of the note.
Note: The name of the note.
Freq: The target frequency for the note, or for the NAF study model, the predicted playing frequency.
Im(Z) Corr: Used for calibrating reed instrument mouthpieces. The discrepancy of the prediction model in overall reactance or admittance of the instrument at the specified frequency.
Air Speed: An estimate of the average speed of the air leaving the windway, in relative units. We expect an instrument to be easier to play if the air speed required for adjacent notes isn't too far apart, and if the air speed required increases predictably from the bottom of the range to the top.
Air Flow Rate: An estimate of the rate of flow of air leaving the windway, in relative units. This gives an indication of how long you can sustain different notes. It also allows some comparison of the relative air requirements of different whistles.
Gain: The overall loop gain calculated by the model at the specified frequency. We expect the note to sound only if the gain is greater than one.
Q Factor: An estimate of the Q Factor at the specified frequency. A higher Q factor indicates a sharper resonance. We expect a larger tube to have a higher Q at low frequencies, and a smaller tube to have higher Q at high frequencies. See Michael J. Moloney and Daniel L. Hatten, "Acoustic quality factor and energy losses in cylindrical pipes," Am. J. Phys. 69 (3), March 2001, p. 311.