SOUND The extract of a sound is continuous ( black )

SOUND The extract of a sound is discrete ( red )

The quality factor of oscillatory system (corps of a violin ).Q = 15-20

In a zone of high (middle ? ) frequencies it is necessary to have only some bars of radiations....

(1) 249Hz..........(2) 263Hz

2

1

This sound

Pay attention to the front of beginning of oscillations. And relation of amplitudes 1 and 2 modes of oscillations. Also on timbre ( colouring ) of the sound first and second tone.  (It is the indicator of impedance.....)

For example: Area (site) of low frequencies

It is unessentially " who is who " among resonances. For good sounding G...is important to have a rise of amplitude of a frequency characteristic  without severe dips. The similar situation should be for middle and high frequencies.

For higher frequencies:

enlarge

Stradivari 1736

3000 - 4500 Hz

There is yet the lower oval!

I think that the concept "formants" must form the basis of the general concept of the violin sounding. The instrument will reproduce mostly those harmonics of strings the frequencies of which are close to the body resonances. This is the matter of key importance in understanding the nature of the violin sounding. The eigenmodes (body resonances) represent a complex phenomenon. We can give the main types of the resonances: 1. Helmholtz resonance (A0). 2. Resonances of the body parts and the construction as a whole (C0, C1, Bi...). 3. Resonance of a body stipulated by the linear dimensions (linear resonance), one of them is A1. 4. The individual resonances of the body, decks (resonating sites of a lower and upper deck) - they can be detected by Fuhr or vibrating methodology. 5. Transitional processes on low frequencies (the moment of the emergence of oscillations and the moment of vibrato) 6. The moment of impedance and relation of energies. 7. ... Especially strong reproduction of the tones takes place when there is a coincidence of the resonances of the total body or its parts and the linear resonance of the body plus the phase condition (Helmholtz resonator amplifies only those vibration which gives the change of the resonator volume).

Here is a concrete example:

For selection of the high-frequency formants it is necessary to have resonances of sites with frequency which is close to frequency of a linear resonance body. ( In view of a form factor...) Only in this case we shall have strong sounding on high frequencies. I usually try to tune several sites (the condition of a phase! ) on frequency 1170 Hz. Actually it is always in the range 1150-1190 Hz. (I apply glass tubes without rubber insertion - by Fuhr - and vibrator through bridge) Here also appear the effects of speed transformer, damping, pulling of frequencies and so on..

This sound

transformer of a speed

I want to remind the readers a "sacramental" phrase at the beginning of the theme: Simple acoustic calculations show that the potential opportunity of the harmonic sounding of a violin is stipulated by its proportions. But it is only the potential opportunity and for the realization of it some additional conditions are necessary. Above I have given an example of realization of these conditions. About 17 years ago I tried to measure the linear resonances of the body. For neutralizing the resonances of decks I have located the body in plasticine with sand. . I have located the emitter and the acoustic probe (sound)  inside the body and etc...

About ...years ago ( 1982 ) I also constructed the model of a violin based on the "golder section" principle. Here the harmonic relation of linear resonances was fundamental. It was a very beautiful idea. A major chord there  represented  a basis of everything. (You probably know a source of a major chord -  these are (1)2,5,3 modes, but 5 modes are transferred by an octave down). (For example - 100-200-300-400-500 further 500/2=250 and then  200-250-300) For a violin it is F-A-C (350-440-524 or 700-880-1048) F -there is 5 (2,1) mode of a free deck. Upper oval (bout)=160mm, lower bout =196mm. Lenght body = 327mm (It is all inside) Do not accept too seriously these sizes, at that time they had mostly a religious meaning to me:-). 34300cm/(16x2)cm=1050 Hz = C. 34300cm/(19.6x2)cm=875Hz = A. 34300cm/(32.7x2)cm=524Hz = C. A0 = C. (probably B1- = 440 = A and B1+ = 524 = C ....) There are some interesting points more... But! In practice it appears to be more difficult:-) For building up the form of a violin I used one size 75mm and an even bar. All relations and sizes there are in the form.

Please be aware that the problem of violin sounding has many aspects, so here I have presented only a part of the most essential moments (subjects).

Enjoy the life!! The life is continued:-)

Summer 2002

The varnish  drys under the sun

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beginning