It calculates parameters for flutes, and clarinets
I was just wondering how cork to end length is measured for a clarinet?
What? I use TWCALC for whistles…
Yeah but, the latest one at least, has an option to change the wave divisor from 2 to 4 (for clarinets)
Another question is how do you choose hole sizes - just trial and error - looking for a flat graph?
I choose hole sizes that will give the best hand comfort and still produce a nice sounding whistle. If the holes are too small then the note will sound weak compared to ones with a larger hole.
Yeah I haven’t really figured out the graph yet, I think the flatter the better but im REALLY not sure.
S’mae Cwfawnder
The member from the Palace of Righteous Justice has summed up the hole size question well; there is also a need to keep the sizes as similar as possible to avoid volume disparities.
John S
Holy Shmokes!!! Someone here knows what Cyfiawnder means!!! I thought it was nothing but C Gaelic speakers here!!! Nice to toss some good old Cymru into the mix 
Didn’t I already mention the volume/hole thing?? 
I don’t know about the Palace of Righteous Justice, But I am a 1st Level initiate Bardagh Grade Awenydd in the Welsh Druidic order Nemeton Awenyddion. Cyfiawnder is the name I took uppon myself, because it is in line with my beliefs. Boy the things I would do to G.W. Bush 
I wouldn’t mind dealing some justice to him. Cyfiawnder is also the Closest thing that I could find to the meaning of my Given name Justin. Justin Means justice… so… My spirit guide is the wolf and the Red Tailed Hawk. My God form Is Cernunnos.
Grant, O Gods thy protection
And in protection, Strength
And in Strength, Undertsanding
And in Understanding, Knowledge
and In knowledge, JUSTICE
and in Justice, The love of it
And in that love, The Love of all Life
And in that Love of Life
The love of the Gods and all Goodness
I am the rain drop in the Ocean
I am the hawk that watches the rabbit
I am the Birch that Begins all Jurneys
I am the Yew that sees those Jurneys end
I am the the Light of Inspiration
Who but I knows the paths To Illumintaion?
Who but I knows the road to Righteousness?
Y Guir Yn erbyn Byd
/|\Peace in the light/|
WSSL
Wisdom
Self Honesty
Self Responsibility
Light
Cyfiawnder
I am in the process of writing a program that is very similar to TWCALC. I intend to release the source code and executables as GPL software.
I want to be able to do optimizations based on things like the cutoff frequency or to say where I want the holes, and the prog will tell me (about) what size to make them.
The program will be GUI based and portable between MAC, U*IX, and Windblows. I have most of the math part done and I am starting on the GUI interface.
Anyone have any ideas as to what may be useful? Anyone want to help? (Written in C and C++)
Other comments?
That sounds like a good project…
Just based on my limited experience with twcalc -
- hole size suggestions (as you describe) would be nice, with option to limit to fractional drill sizes or custom (so they need to be filed after drilling)
- a proper file save/load dialog, with one default file loaded at startup
- example files (starter designs)
- good help file or documentation
- auto-recalc when a parameter is changed
- diagram/plan printout with dimensions
- dialog to choose pipe and schedule, which will enter the correct bore and wall thickness automatically
- setup dialog, or have the program remember setup (metric vs imperial for example)
TWCalc is written in good old fashioned Visual C (no stinkin ++). If you want a copy of the source, send me a personal email (click on email button below).
I’m designing TWCalc with the goal of monitoring Local Cutoff frequency more closer - as it is the key to designing consistant sounding toneholes.
What would be nice is some AI type logic that tries a given set of standard drill sizes, human hand stretch limitation parameters with the goal of consistantly increasing local cutoff up the scale and let the computer calculate the optimum set.
You might want to make use of some of my code.
Re. The graph - flat is good with a little rise as it increases in frequency.
It’s a linear graph and would ultimately be better if it were expressed exponentially.
Clarinet mouthpieces will give you problems with the length. Make a piece of tube with a Clarinet mouthpiece on it. The shape of mouthpiece and frequency of the beating reed is going to distort the size calculation. (this is Benade’s book) Using a reference piece of tubing, you can adjust the reference for the right note and then compare to the theoretical size - use the difference as an offset for and other piece of tubing of the same diameter for any different key.
Thanks heaps. Yes, that offset could be regarded as the ‘length’ of the mouthpiece - to be added to any given length for the total ‘cork to end’ length.
I asked my HAL 5000 if it could help, but it just said “Sorry John I can’t do that”
Well poke her in her big red glowing glass eyeball! Gotta love obscure 2001 stuff
The physical length of a reed mouthpiece and the ‘musical length’ are not the same value. The area inside the mouthpiece plays havoc with this parameter. Maybe I could have a ‘mouthpiece offset’ field.
Load/Save dialogs will be added later.