Cordes en boyau pur et filetées

les cordes boyaux

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Choosing the strings

Playing on guts strings is a journey, I share ideas and comments based on my own experience and research but I encourage you to make your own research on the topic.

Understanding tension and forces on your instrument will help you find the best strings for your set-up. Tension is a word often used and heard, but it is also something we feel when we play.

mass - DENSITY

The mass of a string is the amount of matter contained by the string.

The matter of the string: plain guts
Density of the gut: number of Kg/m³

About the wound around the guts: it allows the string maker to produce a thinner string with a theoretical equivalent of plain gut string (because material like silver and copper are is heavier than the guts).

tension - tension force -

The tension force is the force that is transmitted through the string when it is pulled tight by forces acting from opposite ends. The tension force is directed along the length of the string and pulls equally on the objects on the opposite ends of the string.

FTENS

(A tension force is measured in Newtons, the newtons are then converted in Kg-force : One kilogram is equal to 9.81 Newtons.)

How to define the TENSION-force and the diameter of the string needed for your instrument?

Which diameter ?

The thickness of the plain guts string depends on the string length of the cello for the pitch and the tension force needed.

Very thin string may be too meticulous and picky, and will break easily,
Very thick may be dull and hard to put into vibration.

How much tension force does your instrument need?

For example, you string lentgth is 69cm, you tune in 415, if you play an A string of a diameter of 1.20, the tension force of the string is be 12 kg force etc.

Are 12kg enough or too much for your cello to sound well?

To know if you need more or less tension force on your string, you can increase the tension of the string (go sharper) and see if it reacts better, then do the opposite.

Note: an important pressure on the sound-board might damps the sound if the bridge is too high.

Calculer le diametre de ses cordes

Gamuts nous a simplifié les choses... Pour savoir quel diametre choisir, il suffit d'entrée la fréquence de l'accord (si 415 Hz, 392Hz 440Hz etc...), la longueur de corde, et la tension de la corde en Kg désirée.

Voici un exemple (sur mon violoncelle baroque) avec une tension égale sur chaque corde de 13kg.

Le poids a été calculé en considérant l'angle de la corde au dessus du chevalet (155° sur mon violoncelle), la longueur de corde (712mm) et la fréquence de l'accord (415Hz).

CALCULER

comparasion To understand the consequences of the string length and the Tension-force

Two examples: one with a string length of 69cm and one with a string length of 71cm on equal tension.

Calculer le diametre de ses cordes

Voici un exemple (sur mon violoncelle baroque) avec une tension égale sur chaque corde de 13kg.

Le poids a été calculé en considérant l'angle de la corde au dessus du chevalet (155° sur mon violoncelle), la longueur de corde (712mm) et la fréquence de l'accord (415Hz).

CALCULER

I. Mon Experience

I play on heavy tension but not equal tension on all strings

Mon premier jeu a été posé et choisi par Valentin Oolmüller - Pure-Corde à Potsdam.

Cordes à tension égale: 13kg par corde

I: Toro sheep gut diskant by Toro
II: High twist Darmsaite
III: Ø 2,70mm - Pure "triple"
IV: Silver wound gut string Equiv. Ø 4 mm

J'ai ensuite exploré différentes marques, ainsi que d'autres tensions avec l'aide de Bastian Muthesius, à Berlin, parmi les marques de cordes essayées: Aquila, Liedmeier, Kürschner, and Gamut Strings.