The Kasha Guitar represents a major effort to improve
upon the traditional classical guitar. It uses modern physics,
acoustical theory, and new materials for construction and finish,
to go beyond the limits of an instrument which has largely reached
the maximum of its design potential. The finest (that is to say
the most sensitive, responsive and resonant) classical guitar
converts only about 5% of the energy of a plucked string into
sound. The rest becomes heat, as one’s guitar literally
warms up with playing. The energy available for sound may be
heard as great volume, or as great sustain, but not as both.
This unfortunate trade-off is enforced by the limitations of
a design basically settled upon in the 1870’s, with only
subtle changes in internal structure and materials since then.
In the 1960's, a physical chemist named Michael Kasha
purchased a classical guitar for his son. Although he didn't
play guitar himself, Dr. Kasha thought it just didn't sound as
good as it could. Upon further examination inside the instrument
he decided that some changes needed to be done so that every
note was clear and strong. While he earned Doctoral degrees in
three disciplines, Dr. Kasha’s astonishing intellect became
focused on applying modern scientific theory, exact tools of
measurement, and new construction materials, to develop a radically
re-designed and potentially far more capable “classical”
guitar. Richard Schneider, then a master builder of traditional
classical guitars, began a 30-year collaboration with Dr. Kasha,
resulting in a series of constantly evolving and improving instruments.
In an effort to create an instrument converting perhaps
7 or 8% of string energy into sound, and thus allowing greater
volume AND greater sustain, while all the time insisting on perfect
pitch and balance in all notes struck anywhere on the neck, the
Kasha design focused heavily on 5 areas...
First, the neck was made very heavy and rigid, while
keeping normal dimensions and a graceful shape. This prevented
a loss of string energy into useless vibration of the neck. Subsequently,
this saved energy helps prolong excitation of the soundboard
via the bridge. The weight of the neck also increases treble
response.
Second, the impedance dependent bridge, shaped like
a wedge rather than the traditional rectangle, was designed to
more efficiently transmit bass tones to the bass (left) half
of the soundboard, and treble tones to the treble (right) half.
It was made to have as little mass as possible to allow ready
responsiveness.
Third, the soundboard was given a decidedly thinner
bass half, and thicker treble half, again to respond more readily
to bass and treble tones. The soundhole was moved from its centerline
position to the upper-right area of the top, an area found to
be almost “silent”, hence useless in sound production.
This move tremendously strengthened the top and created a much
larger vibrating area than in traditional designs. It also allows
the braces that affect the midrange to be the appropriate length.
Fourth, a truly radical bracing system on the underside
of the top became a crucial design element. Again, it was designed
to reinforce production of bass tones by the bass half, and treble
tones by the treble half of the top, while taking advantage of
every possible square inch of the top surface for creation of
a truly big sound. This system also allows the bridge to move
more freely in a rotary as well as up-and-down manner, adding
sustain and richness of harmonics.
Finally, for the back, an elegant and complex bracing
system in conjunction with the use of tonewood allowed it to
move like the diaphragm of a speaker, reinforcing the profundity
of bass, middle, and treble notes.
These complex instruments are slow and exacting to
produce, hence expensive and rare. Every part is hand-built and
placed “just so”. They are solidly built to last virtually
a century. When compared in play-offs against superb guitars
of traditional design, they display a rich and profound tone
sometimes compared to a grand piano. They lend themselves splendidly
to true classical music. The recent recording of Bach’s
Goldberg Variations by Kurt Rodarmer makes this point brilliantly.
These guitars enormously impressed Andres Segovia, and are today
in the hands of some of the world’s finest players.
by Vince Meyer
Billings, Montana
1997
(used by permission) |
