Kasha guitar design
Charles Tauber
design, as originally defined by Dr. Michael Kasha and Richard Schneider.
During these years, I have:
1. made one Kasha guitar;
2. played a number of Kasha-based guitars built by other makers;
3. played a $10,000 Kasha-design guitar made by Richard Schneider;
4. heard 20 concert guitars - including one made by Schneider - played
side-by-side on stage in a concert setting by two world renouned classical
guitarists;
5. spoken with Richard Schneider about Kasha guitar design;
6. played a Schneider-designed Gibson Mark Series guitar - a steel string
incarnation of the Kasha design;
7. studied and researched published and un-published technical literature
written by Schneider and Kasha on "scientific guitar design"; and
8. spoken with two "graduates" from his Lost Mountain (Kasha guitar design)
Seminars - one of whom had a masters degree in acoustics.
As a mechanical engineer and a luthier, my conclusion is that, while the Kasha
instruments are visually "interesting", they offer little or no significant
advancement in guitar design. Furthermore, most of the science used in the
"scientific design" is either "old hat", based upon unsubstantiated premises or
is oversimplified to the point of being unapplicable to a real guitar.
The very long scale length typical of Kasha designs make the Kasha instruments
very challanging to play for a musician with average length fingers. The
complexity of the construction of Kasha designs adds many hours to the making
of the instrument - Schneider said that it takes him, on average, 1000 hours to
make one of his guitars, while 300 hours is typical to make a "traditional"
design - while adding little or nothing to the quality of sound or playability
of the finished instrument.
All that said, if you are still interested in plans for a Kasha model, they can
be purchased from Luthier's Mercantile.
If anyone is interested in a more detailed discussion of Kasha guitars, let me
know.
Charles
Sean Barry
Charles:
I'd be very interested in your further thoughts and discussion on the
Kasha design. I'd have emailed you about it, but your address is
missing. Please post more...
Sean Barry
sjb...@ucdavis.edu
Charles Tauber
Okay, you asked for it. Since you didn't give any indication of where to start,
I'll start at the beginning.
THE single MAJOR defining premise of the Kasha guitar design (KGD, hereafter)
is based upon the question of how the energy (motion) of the vibrating guitar
strings is transfered to the guitar body for amplification. There are three
possible "modes" of transfer, each involving the "coupling" of the stings to
the top via the guitar's bridge. The first is by having the bridge move
parallel to the guitar top, causing the top to alternately elongate and then
compress along the length of the guitar top. This is almost certainly not the
MAJOR mode of transfering the string's energy to the guitar body. The second
possible mode of transfer is by the bridge "pumping" up and down, alternately
pulling and pushing the guitar top like the skin (membrane) of a drum. The
third possible mode of transfer is by the bridge rocking forward and back,
towards and away from the guitar neck.
The KGD ASSUMES that the third mode of energy transfer is the PRIMARY mode.
While there is no question whatsoever that this is a major mode of transfer, to
the best of my knowledge, no one has ever shown (experimentally or
theoretically) that this is the PRIMARY mode of transfering the motion of the
strings to the guitar body. I can show, on the back of an envelope, using
simple first year physics, that it is unlikely that this mode is the PRIMARY
mode of transfer - it is likely the "pumping" action that is the primary mode.
Why is this so important?
Well, most of the distinguishing KGD features are based upon the assumption
that the major way in which the string's motion is transfered to the guitar
body for amplification is by the bridge rocking forward and aft about a
stationary point (a "node"). This stationary point, it is assumed, is the
saddle. The first, and primary distinguishing design feature of the KGD to be
based upon this assumption is the bracing of the guitar top. (Guitar makers
generally agree that the single most important sound-producing component is the
guitar's top; its design and construction are very important in producing the
final sound that an instrument has.)
Thus, if you continue with this assumption, as Kasha does, having braces on the
underside of the top which run directly under the bridge, more or less from
soundhole to butt, impeeds the rocking motion of the bridge. Thus, the
necessary bracing pattern must not have any brace which continues under the
bridge. However, since, it is argued, the saddle does not move - it is a node -
you can place a brace directly under the saddle that traverses the width of the
guitar. For traditional guitar top bracing - steel string or classical - this
is a radical departure. The bracing pattern Kasha and Schneider designed has
short braces extending radially from the saddle with a "node bar" traversing
the width of the top directly beneath the saddle.
Now, proof that Kasha was on the right track with his hypothesis could come in
two froms. First, the guitars produced with this bracing pattern could be
dramatically better than guitars braced with traditional patterns. Second,
scientific testing could be performed which would be designed to answer how the
bridge moves when the strings are plucked. Since the Kasha designs have been
around - and continue to evolve - for about the last 20 or so years and haven't
been adopted by more than a few luthiers, it seems a fair statement that
neither the musicians buying guitars or the luthiers making guitars are all too
convinced that the bracing system (and other KGD features) produce superior
instruments. While fairly extensive scientific testing has been done on
violins, to the best of my knowledge, no one has researched the question of
exactly how the guitar bridge moves and transfers the string's motion to the
guitar body.
In short, Kasha has started with a hypothesis which he ASSUMED to be true,
designed a top bracing system based upon that assumption, and has not been able
to produce guitars based upon that assumption that have a sound quality that is
superior to traditional guitar designs. That suggests to me that his hypothesis
is probably not valid (ie. not true).
The top bracing, while being very radical, is only one of a number of unique
features of the KGD. Others include "impedence matching", "inertial weighting",
"alternate" aesthetics, VERY long (string) scale lengths, imobilizing the neck,
etc. All topics for another day, if you're interested.
Charles Tauber
tau...@candu.aecl.ca
Gregory Patten
afford the $40 each that the only supplier I've found so far is asking?
The other alternative would be a bass amp (not the speaker or cabinet -
I've got those) that I could install in the head of this combo. Anyone
got any (inexpensive) ideas. ;-)
Larry English
>Charles Tauber <tauberc> wrote:
>>For the last 15 years, I have followed the evolution of the Kasha guitar
>>design,
>>know.
>>
>>Charles
>>
>really heard of this new "radical" design. Can you tell me something
>about the new design?
i also am very interested in this..
has there been anything done in the bass arena with kgd?
i don't want you to be typing ad infinitum though, is there a printed
or webable version of any of this?
thx,
wle.
David Gandolfo
I've often wondered what the attraction to the Kasha design is.
Your comments were very interesting. Thanks.
David
Sean Barry
If Charles will permit me to give a short (for me) answer to that...
Dr. Kasha "redesigned" the acoustic guitar during the late 1960's and
early 1970's, and his new design included a much longer scale length than
usual, an assymetrical bridge, a somewhat rounder body than usual, and a
radically different bracing design (Charles has already detailed much of
the design departures and the reasoning behind them). The Gibson Company
adopted the design features that were amenable to mass production into the
"Mark" series guitars of the mid and late 1970's. The line more or less
flopped, and was dropped about 1978. The two most prominent luthiers who
have adopted the Kasha design are Richard Schneider (of Michigan?) and
Steve Klein, who I believe is still in Sonoma, California. Klein's
designs, at least in the past, have departed radically even from the Kasha
platform, but his work is peerless and his instruments are true
masterpieces. As far as I know, Schneider confines his work to the Kasha
design, and he remains its principal exponent. I have never seen a
Schneider guitar, but he has an outstanding reputation as a master
luthier. Both ask (and receive) premium prices for their work. Read
Charles Tauber's second post in this thread for a good scientific
analysis of the design.
Sean Barry
Bruce Taylor
> As a mechanical engineer and a luthier, my conclusion is that,
> while the Kasha instruments are visually "interesting", they
> offer little or no significant advancement in guitar design.
> Furthermore, most of the science used in the "scientific design"
> is either "old hat", based upon unsubstantiated premises or
> is oversimplified to the point of being unapplicable to a real
> guitar.
This is *very* interesting. Most of what I've read about Kasha
guitars has come from proponents of the system.
You do not think the Kasha-Schneider designs provide a better
sound--but is it different? I've heard the claim that Kasha
guitars are louder. Are they? Do they give a brighter, boomier,
warmer, or more balanced tone?
Bluemuse
Well, for what it's worth I was able to find a 7868 for my Ampeg Jet just
by walking into the local electronics shop and asking if they had any. I
think it was $18.
--Bob Farace
"I only believe in fire." --Anais Nin
Bob Laughlin
: For the last 15 years, I have followed the evolution of the Kasha guitar
: .........
I find Charles's analysis of the Kasha design very interesting. I made one
Kasha style instrument, a small-bodied, 12-fret neck steel-string with a
Douglas Fir top. However I did so many things different on the instrument,
in addition to the Kasha-style top bracing, that it's difficult to assess
it on its Kasha merits. The sound was unusual, loud, better for single
string picking than chords (probably the fir top).
Anyway, I tend to doubt the theory of the primacy of bridge rocking
myself. It would be interesting to have some Kasha-style builders defend
it here.
I think what it comes down to is that you can start from any theoretical
position and build excellent instruments. Your design evolves from there.
Look at the variety of sounds produced from luthiers using traditional
bracing patterns. One thing I do like is the aesthetics of the Kasha
instruments I've seen. They are things of beauty.
Ken Rice
bridge-rocking mode is clearly the primary mode--it's hard for me
to imagine it being otherwise. Like he said, I can prove it with
basic ideas from engineering--oh well. It's also easy to see by
using a laser reflected from a mirror attached to the bridge.
In answer to the question about Kasha basses: There were two Kasha
system basses in evidence at the Guild of American Luthiers this
summer--one of the mine. I thought that they were clearly the class
of the field in the bass-listening evaulations. I believe that the
new Taylor acoustic bass is also a Kasha design (ala Steve Klien).
There are various ways to implement Kasha ideas. Schneider uses an
extremely complex variation. I use a simpler one. My bass took about
200 hours in the shop--about the same as a "conventional" instrument.
Also, I believe that the Gibson Mark series failed because of
(1) being marketed to the C&W sector, which tends to favor bass-
boomy dreadnaughts, and (2) I've heard that the production units
had the internal bracing backwards. There's a lot more to that
story than just "Kashas are bad".
I'm using Kasha-system design ideas on a new autoharp this winter,
and will probably never build an instrument without some type of
radial bracing--it just makes sense to me, and I build best when
I'm working on something that I understand. Like quantum theory and
lots of other things in science and engineering--it may not be
right, but if it helps me I'll use it!
Ken
A Hopkins
: strings is transfered to the guitar body for amplification. There are three
: possible "modes" of transfer, each involving the "coupling" of the stings to
: the top via the guitar's bridge. The first is by having the bridge move
First, really good thread Charles , thanks
Of the three modes, it is easy to visualize mode three rocking the bridge
as the apparent string length changes. It is possible to imagine a small
contribution from mode one if we consider energy transfer to the nut,
bowing the neck slightly and coupling into the body via a rocking heel
block. Yea I know its a long trip ( stretch ) but .... As to mode two
I have a hard time seeing how the vibrating string can excite this mode.
Could you give some detail here please? I don't disagree, I just dont
understand.
: bridge. However, since, it is argued, the saddle does not move - it is a node -
: you can place a brace directly under the saddle that traverses the width of the
: guitar. For traditional guitar top bracing - steel string or classical - this
: is a radical departure. The bracing pattern Kasha and Schneider designed has
: short braces extending radially from the saddle with a "node bar" traversing
: the width of the top directly beneath the saddle.
Here, I believe, Kasha really misses the mark. It is well known that the
rocking (from treble to bass) is one of the defined modes of guitar
top vibration. To intentionally kill this with a "node bar" seems counter
productive.
Snip , lotsa good stuff
Ray Hopkins
70244
>neither the musicians buying guitars or the luthiers making guitars are all too
>convinced that the bracing system (and other KGD features) produce superior
>instruments.
This may be, but I think you are underestimating the tendency among musicians
be an incredibly (incredible for people who think they are "rebels") conservative
when it comes to instruments. Few musicians want a unique instrument, most
of them seem to prefer whatever peer pressure has determined to be the norm.
This same problem can be seen historically when you examine the problems that
the modern piano had in being accepted upon its introduction. It was (and is)
a clearly superior instrument, but it was too radical a change for many of the
periods musicans.
I think that it is too soon to judge whether acceptance (or lack of acceptance)
of the Kasha design as much bearing to whether or not it is a technically
superior design.
Radical innovations have usually had problems in acceptance in most fields.
Sean Barry
: This may be, but I think you are underestimating the tendency among musicians
: be an incredibly (incredible for people who think they are "rebels") conservative
: when it comes to instruments. Few musicians want a unique instrument, most
: of them seem to prefer whatever peer pressure has determined to be the norm.
: Radical innovations have usually had problems in acceptance in most fields.
...unless there is a perceived or real need for the innovation.
Actually, it seems to me that *most* accomplished musicians would go for
any instrument, regardless of appearance, origin, or pedigree, if it plays
easily and sounds great. Had the Kasha design, regardless of version,
panned out as a true tonal revolution, it would have caught on and
competition would have brought the price down. But, as we have discussed,
the typical Kasha design was difficult to play and did not sound
materially better than other comparably-sized guitars. It doesn't matter
who is correct about bridge rocking, brace patterns, etc--the fact is, as
Charles said at the outset, though the design was unique the sound and
playability were not.
SB
Charles Tauber
>This is *very* interesting. Most of what I've read about Kasha
>guitars has come from proponents of the system.
>
>You do not think the Kasha-Schneider designs provide a better
>sound--but is it different? I've heard the claim that Kasha
>guitars are louder. Are they? Do they give a brighter, boomier,
>warmer, or more balanced tone?
>
>
Bruce,
There is no question that Kasha guitars do sound different than traditional
classical guitars. Unfortunately, what they aim to achieve - "balanced" tone
from string to string and identical timbre across the entire range of the
instrument - no longer has the characteristic sound of a classical guitar.
Should I invent a new instrument that looks like a flute but sounds like a
clarinet and then insist that it is an improved flute sound? An audience of
classical guitarists listening to a variety of hand made instruments in a
concert setting didn't seem to prefer the "new" guitar sound produced by the
Kasha guitar.
Are Kasha guitars louder. In the same concert setting, the Kasha played - made
by Richard Schneider - was louder than some, and not as loud as others. It was
the only non-traditional design of the twenty guitars played. (The best of the
lot was made by Jose Romanillios, a great guy that I learned alot from, but
that's another story.)
The classical guitars I've played and heard of the Kasha design have every
string at every fret sound like an open "g" string - "thick" sort of timbre,
relatively "round" and warm. Thus, the guitars were not brighter, but more
thick - or in the extreme, "mushy". The most noteable thing lacking in the
Kasha designs I've played and heard is that the treble strings have no "bite"
and the bass doesn't have a real punch - they all sound like "g" strings. But,
this is the aim of the design, to create an instrument with uniform timbre.
Unfortuneately, removing the characteristic changes in timbre from string to
string and from one position to the next results in a decidedly non-guitar like
sound. In some cases, it's almost difficult in a blind test to determine what
kind of instrument is being played - whether it's a guitar or some other
instrument.
The only steel string Kasha-based guitar I've played is a Mark Series Gibson.
It was so horrible on every count, that there is nothing that I can say was
good about the tone of the instrument except that they stopped making them.
There are however, luthiers making steel string guitars using varying numbers
of the Kasha design features. I've not played these, and hence, can't comment.
Charles
Charles Tauber
Read
>Charles Tauber's second post in this thread for a good scientific
>analysis of the design.
>
>Sean Barry
>
Actually, so far, I've only discussed one design aspect of many that are
incorporated in the Kasha design. If people are insterested, I'd be happy to
discuss others.
Charles.
Ps.
Steve Klein does make beautiful guitars. I have not had the pleasure of playing
one. Perhaps the best known musician to play a Klein is Joni Mitchel.
Charles Tauber
>This may be, but I think you are underestimating the tendency among musicians
>be an incredibly (incredible for people who think they are "rebels") conservative
>when it comes to instruments. Few musicians want a unique instrument, most
>of them seem to prefer whatever peer pressure has determined to be the norm.
>I think that it is too soon to judge whether acceptance (or lack of acceptance)
>of the Kasha design as much bearing to whether or not it is a technically
>superior design.
>
>Radical innovations have usually had problems in acceptance in most fields.
>
>
No, I don't think I'm underestimating the tendency among musicians to be
conservative. I know that musicians are generally very conservative. However, I
believe that if a musician was given a vastly superior instrument to play,
albeit non-taditional, the musician would prefer it. I don't believe that the
Kasha design has produced instruments that are superior in sound and
playability to other well made traditional guitars.
Also, keep in mind that Kasha guitar designs are now approaching 30 years old.
While that is historically not a long period for accepting innovation, I think
it should be long enough to prove the point, if it can be proved. (Kasha stated
20 some odd years ago, that it would be so obvious that his design was such an
advancement in guitar design, that in 5 years time everyone would be building
guitars according to his principles.)
Charles