US3884109A - Method for improving the resonances of stringed instruments - Google Patents

Abstract

A process whereby a stringed instrument may be altered after assembly so as to achieve maximum efficiency and tonal quality. Sandpaper, manipulated through the end pin hole of an assembled instrument is used to change the prime wood tones and phase differentials of the resonant cavity to optimum levels.

Description

United States Patent [191 [111 3,884,109 Johnson May 20, 1975 METHOD FOR IMPROVING THE RESONANCES OF STRINGED INSTRUMENTS Inventor: Charles s. Johnson, 5208 s. 12th St., Arlington, Va. 22204 Filed: Apr. 26, 1974 Appl. N0.: 464,346

References Cited UNITED STATES PATENTS 4/1963 Westlake 84/275 3,136,196 6/1964 Charlesworth 84/275 Primary ExaminerJoseph W. Hartary Assistant Examiner-John F. Gonzales Attorney, Agent, or Firm-Larson, Taylor and Hinds 5 7] ABSTRACT A process whereby a stringed instrument may be altered after assembly so as to achieve maximum efficiency and tonal quality. Sandpaper, manipulated through the end pin hole of an assembled instrument is used to change the prime wood tones and phase differentials of the resonant cavity to optimum levels.

5 Claims, No Drawings METHOD FOR IMPROVING THE RESONANCES OF STRINGED INSTRUMENTS FIELD OF THE INVENTION This invention relates to the manufacture of stringed instruments, and, more particularly, internally altering an assembled instrument so as to achieve maximum efficiency and tonal quality.

BACKGROUND OF THE INVENTION It is well known in the art that the tops and backs of violins must be constructed to sound more than a semitone, yet less than a full tone apart for maximum resonance. When they are exactly equal or more than a full tone apart, a poor instrument results. In addition, the frequency peaks of top and back should alternate. The tonal requirements of a stringed instrument are explained in an article entitled The Physics of Violins, by Carleen Hutchins in Scientific America, Nov. 1962, page 79. v

All of the required work to achieve optional tonal quality is done prior to assembly of the top and back, and, discounts the effect of varnish, which is unequally applied due to the different densities of wood employed, usually, maple and spruce. Instrument makers have for hundreds of years been preoccupied by the individual sound of the top and back of an instrument, and the mystery of a secret varnish, and have had to assume that the whole, when finished is to equal the sum of its parts. Individually these parts are most vibrant at their outer edges, however, when glued together the situation is reversed and it is the center area of the instrument that is most vibrant. Thus, once assembly of the individually designed parts was accomplished, nothing could be done to significantly improve the instruments tonal qualities. Air resonances could be altered by changing the size of an instrumentsfhole, but, as described in the aforementioned article, such a large increase in the size of an f hole would be required to alter the air resonance by a relatively small amount, that this process alone is impractical.

SUMMARY OF THE INVENTION According to the invention, a process is provided whereby the prime wood resonance of an intrument is altered, after assembly, to achieve maximum efficiency and tonal quality.

The inside of the back of an assembled violin is sanded by a stiff wire inserted through the pin hole at the base of the instrument. In order to utilize the pin hole for this process, the tail piece loop, usually fastened to a button in the pin hole, must be externally clamped, so as to permit tuning the instruments strings to concert pitch. By carefully sanding the back of the instrument, the prime wood tone of the instrument and the air resonance tone are brought into consonance, preferably a muscial fifth apart. In a similar manner, the bass bar is sanded to achieve proper phasing of the resonance tones.

DESCRIPTION OF THE PREFERRED EMBODIMENT As described in the above mentioned article, the cations of the two chief resonant tones, the prime wood tone and the air tone, are essential to the production of high quality instruments. These tones are detectable by sliding ones finger down the string. An individual with a musically trained ear can detect the sound level peaks at these two locations, but a sound level meter, commonly referred to as a VU meter, allows even the untrained ear to detect thesetwo. sound peaks. While the present invention is applicable to all stringed resonant body instruments, a preferred embodiment is described in relation to a violin, since the parts thereof are well known to those skilled in the art.

The prime wood tone and the air tone are reflected in every note that is played on an instrument. The objective of the present process is to bring these two tones in consonance to create a perfect chord. For example, the two tones could be set a musical fourth, fifth or sixth apart, each resulting in a different quality chord. According to the preferred embodiment, the musical fifth is selected. Ideally, this fifth interval should correspond to the middle two strings of a violin, A and D, but any chord may be selected. As mentioned in the above article, the resonant peaks of a good Stradivarius instrument have been located at approximately G sharp and C sharp, relatively close to A and D, while inferior instruments have their resonant peaks a muscial seventh or more apart.

In order to'adjust these two resonance peaks, the instrument must be fully assembled, strung, and tuned to concert pitch. Since a feature of the present process involves working through the end pin hole of the instrument, the button, around which the tail piece end loop is usually fastened, is removed. The tail piece must be temporarily fastened to allow concert tuning of the instrument. This fastening can be achieved by securing a nylon ribbon or other strong material to the tail piece end loop, bringing the ribbon around the end of the instrument, up the back of the instrument and fastening it to the back of the fingerboard, thus straddling the pin hole.

In an alternative embodiment, a clamp, similar to the clamp of a chin rest assembly is fastened to the end of an instrument with the tail piece end loop secured to it.

According to the invention, the air resonance tone is located first and brought as close as possible to D by increasing the size and shape of the instruments f holes. The technique of changing air resonance by changing the size of the f holes is known in the art.

The prime wood tone is then brought into consonance by sanding the inside of the instruments back piece. A small piece of sand paper, about the size of a quarter, is dropped into the air chamber through an f hole. The sandpaper may be reinforced with a thin metal backing. A piece of stiff wire, for example, coat hanger wire, bent and sharpened at one end is inserted through the end pin hole, and used to manipulate the sandpaper. By repeating the steps of gently sanding the inside of the back of the instrument and testing the location of the prime wood tone, the latter can slowly be brought into consonance, at the desired interval (i.e., a fifth) with the air resonance tone.

While the proper interval between resonance peaks is important, optional performance is achieved when these tones are in phase, since out of phase vibrations will tend to conceal each other. In a manner similar to that described hereinabove, the bass bar is gently sanded by a piece of sandpaper manipulated through the end pin hole by a stiff wire. This adjustment is very critical and the correct in-phase point can be missed. A VU meter can aid to the location of that point as the sound level of the instrument, when the resonant tones are in-phase, is dramatically higher than when out of phase. If the in-phase point is missed, additional sanding of the bass bar will eventually bring the in-phase point back again. The necessity for proper phasing is illustrated by the very existence of a bass bar, which was originally designed to ensure proper phasing of various parts of the instrument and not for support.

Thus, the prime wood tone and air resonance tones can bebrought into consonance and in phase after the violin is fully assembled.

The temporary fastening means is then removed, the button inserted in the end pin hole and the tail piece end loop placed around it, thereby permitting final stringing.

Although the invention has been described with respect to an exemplary embodiment thereof, it will be understood that variations and modifications can be effected in these embodiments without departing from the scope and spirit of the present invention.

I claim:

1. A processfor improving the resonances of stringed instruments after assembly thereof comprising the steps temporarily securing the tail piece of said instrument by external means so as to permit said instrument to be strung and concert tuned without the use of the end pin hole of said instrument;

adjusting the air resonance tone of said instrument to a desired pitch by changing the size and shape of the f-holes of said instrument;

adjusting the prime wood tone of said instrument to a desired musical interval from said air resonance tone by the steps of: inserting a piece of sandpaper into the air chamber ofsaid instrument through an f hole thereof; introducing a piece of stiff wire through said end pin hole into said air chamber to permit manipulation of said sandpaper by said stiff wire; and alternately sanding the inside of the back of said instrument and testing said prime wood tone location, until said prime wood tone reaches the desired pitch;

and, bringing said prime wood tone and said air resonance tone into phase by sanding the bass bar of said instrument with said piece of sandpaper manipulated by said piece of stiff wire inserted into said air chamber through said end pin hole.

2. A process as claimed in claim 1 wherein said air resonance tone, said prime wood tone and said inphase point are located by means of a sound level meter (VU meter).

3. A process as claimed in claim 1 wherein the step of temporarily fastening said tail piece uses a piece of nylon ribbon secured to the tail piece end loop of said tail piece, said ribbon positioned along the back of said instrument and fastened to th e fingerboard thereof, thereby permitting access to said end pin hole.

4. A process as claimed in claim 1 wherein said interval between said air resonance tone and said prime wood tone is a musical fifth.

5. A process as claimed in claim 1 wherein said instrument is a violin, said air resonance tone is a D (293 H and said prime wood tone is an A (440 H

Claims (5)

1. A process for improving the resonances of stringed instruments after assembly thereof comprising the steps of: temporarily securing the tail piece of said instrument by external means so as to permit said instrument to be strung and concert tuned without the use of the end pin hole of said instrument; adjusting the air resonance tone of said instrument to a desired pitch by changing the size and shape of the f-holes of said instrument; adjusting the prime wood tone of said instrument to a desired musical interval from said air resonance tone by the steps of: inserting a piece of sandpaper into the air chamber of said instrument through an f hole thereof; introducing a piece of stiff wire through said end pin hole into said air chamber to permit manipulation of said sandpaper by said stiff wire; and alternately sanding the inside of the back of said instrument and testing said prime wood tone location, until said prime wood tone reaches the desired pitch; and, bringing said prime wood tone and said air resonance tone into phase by sanding the bass bar of said instrument with said piece of sandpaper manipulated by said piece of stiff wire inserted into said air chamber through said end pin hole.

2. A process as claimed in claim 1 wherein said air resonance tone, said prime wood tone and said in-phase point are located by means of a sound level meter (VU meter).

3. A process as claimed in claim 1 wherein the step of temporarily fastening said tail piece uses a piece of nylon ribbon secured to the tail piece end loop of said tail piece, said ribbon positioned along the back of said instrument and fastened to the fingerboard thereof, thereby permitting access to said end pin hole.

4. A process as claimed in claim 1 wherein said interval between said air resonance tone and said prime wood tone is a musical fifth.

5. A process as claimed in claim 1 wherein said instrument is a violin, said air resonance tone is a D (293 Hz) and said prime wood tone is an A (440 Hz).