Violin Forum/Message Board

[John Cadd]

The main problem with plate thicknessing is that it`s hard to tell what sounds are coming from the thick and thin parts of each plate . A microphone will pick up sounds from anything in it`s range .
To get past that maybe a laser could be more specfific. Point a tube about one inch diameter close to a resonating violin plate and read the movements via lasers to identify the vibrations .Then translate the laser readings back into sounds. Is that technically difficult or possible ?

[John Cadd]

The idea of measuring sounds from violin areas is already covered in a pdf
" 3D Laser Vibrometry on Legendary Old Italian Violins."
Frankly I could not see any useful information coming out of that .What I mean is --I could not understand what it was telling us . I tried but came away confused.
So I will start another topic on exactly what is in the pdf and hope somebody will enlighten me .

[catbrain]

Maybe you should try a mechanically coupled pickup to minimize sound from other parts. maybe something like a old fashion phonograph needle cartridge.
you can plug those tight up to a microphone input on amps and receivers i think.

[Michael Darnton]

It's been a while, but I think a friend of mine was using a tiny microphone as the hammer for his tap tuning, watching the notes measured at the mic location on his computer screen. Since I'm of the opinion that this type of tap tuning is unmitigated BS and a waste of time, I don't remember any more than that. . . . :-)
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[John Cadd]

There is a video of a man and his wife trying to show how to improve violin sound with a piece of stiff wire and some sandpaper . It`s total nonsense .His wife kept on noodling on her violin playing some nameless practice piece .Very annoying noodling . The demonstration ended with his analysis showing how one tiny bit of the top near the soundhole was affecting the tone . It was about one square inch . We used to read theories like that but to have it on film is so silly. Sadly many valid aspects of violin making and design collapse into spoken commentaries washed over by squeaky violins or as if there was a difference --Squeaky violins washed over by annoying commentaries .
But an oscilloscope screen does show the sum total of the vibrations we hear .It`s a pity we cannot pick apart the information on the screen to give us a genuine understanding of it .The basic screen patterns are said to describe good tone when it`s testing a good violin . Maybe the only effective way to learn is to keep taking apart the same violin and substituting slightly different components till the physical changes can be linked with audible changes . It would need lots of patience, discipline, honesty and money . And a big notebook .

[John Cadd]

One strange idea I saw recently mentioned how much sound came from the outer surface of a violin compared to how much came out of the soundholes . I always thought nearly all the sound came out of the holes. Comparing Strads with Guarneris the Guarneri ribs are said to be thicker.So thicker ,stiffer ribs might keep the top plates less mobile near the edges. That would give less sound near the edges unless a player worked harder to make it louder .
Is that the way old Italian makers might think about their violins?
The air must pump in and out of soundholes otherwise the plates would be restricted . That is a mechanical fact , but does it automatically mean that`s where most of the sound is coming from? Think of it like a Mathematician looking for an absolutely certain proof .

[John Cadd]

I don`t think nit picking exactitude is necessary for violins .I am working on a m3/4 violin made in Luby .The top is far too thick and I took the top off the get it more resonant .
The back diagram for thickness is borrowed from a Strad poster .I roughly sketched the areas with a pencil and drilled the thicknesses (all minus 5mm ) . The Guarneri back shows the soundpost area is clearly the thickest . Just a patch where it`s needed .The curves between the corners is where the wood is reduced into the obvious Loudspeaker type areas . The flat sections where the sides are glued are far too wide and thick .The block areas are massivley thick as well .Children must be using these small violins as clubs to batter each other .
When thicknessing I often think of those Russian Bell makers (Blagovest Bells ) that left the bells as they were cast , without skimming on a machine . The wobbly thickness gave each bell a unuquely individual tone . For a village bell it was only played solo and the tone was always a one off special .