|
|
By
Jeff Loen, Kenmore Violins, Kenmore,
WA
Presented at Violin Society of America Convention, Nov. 2003, Baltimore, MD
|
|
|
|
Abstract
Top and
back plates of Golden Age (pre-1750) violins, violas, and celli show a
number of unexpected characteristics, based on compilation and mapping of
thickness graduation patterns of hundreds of fine instruments. Generally, the
plates are thinner and less precisely carved than modern master-level work. Overall plate
structures are classified as uniform (common on top plates), concentric
(common on back plates and some top plates), longitudinal (less commonly
used on top and (or) back plates), and unclassified (irregular). In addition,
many classic Cremonese violins that are in demand by the best players have
top plates that are carved in reverse of the usual pattern. Rather than
being thick between the ff-holes and thinning towards the edges (normal
graduation), these plates display minimum values near the center and
thicken towards the edges (reverse graduation). An analysis of thickness
distributions on Strad and del Gesú top and back plates shows that del Gesú
plates are, on average, significantly thicker. Moreover, some violins show asymmetrical
graduations, although no systematic asymmetrical preferences were found. Back plates by
Stradivari and Guarneri del Gesú show, on average, a center of thickness at
about the 50% mark, conforming to the position of small pin
holes mapped on violins by three generations of the Amati family.
For
comparison, I include thickness maps of two poor sounding German factory
violins in my collection. These extremely thick instruments
were commercially unsuccessful until they were regraduated. I also include
maps of three fine master level violins, which show minimum thickness in
the upper and lower bouts, and slightly increased thickness between the
ff-holes and at the soundpost location. These makers emulated the classic
plate patterns, but avoided going too thin.
Acoustical
effects of apparent “imperfections” of classic instruments such as very
thin plates, reverse graduation, thickness mottling, and plate asymmetry are
difficult to evaluate, although research suggests that these characteristics
could possibly be beneficial to tone.
|
|
|
