Violin Plate Graduation choices....
...Violin plate graduating refers to the process of thinning the wood of the violin top and back plates (the front and back of the instrument) until the optimum sound production is obtained. Unfortunately, this will not be know until the instrument is completed and played, so most builders rely on past successful graduating plans and hope for the best results.
...While it may not look like it; the plates of a full sized professional violin are only about 2.6 mm thick in many places (0.100"); the ribs are only 1mm thick (0.040"); and the entire violin strung up and ready to play (including the weight of the chin rest - about 50 grams), only weighs about one pound (454 grams).
...If the plates are too thin, the sound produced will be hollow sounding; too thick and the sound will lack the richness and power.
...(Please see separate articles covering "varnish ground layers and effects".)
...We want the finished instrument to have plate tones of 176 HZ top plate; and 198 HZ back plate with the tap tones even all over each plate (except the edges and ends of the plates which are left thicker for strength); so we need to graduate (thin) our plates with this goal in mind.
...I want to share the graduation plan I currently use which is an adaptation of Guarnarie graduation plans to give close to ideal plate frequencies; as well as to keep finsihed violin weight to about 400 grams; ready to play but not counting the chin rest..
...After recording tap tone changes before and after varnishing and varnish ground application, on a number or instruments, I find that there are only small changes that we can ignore. Make the plates the frequency you want when finished and do not worry about varnish and ground effects.
...Your comments and questions are always welcome.
David Langsather, Violin Maker
3425 Fairhaven Avenue N.E.
Salem, Oregon, USA 97301
(503) 364-8685 PST
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