Wound up strings
There are several varieties of wound up strings.
Roundwound
The simplest strings are roundwound. They have either a round core or a hex (hexagonal) core inside, and round wire wound in a tight spiral around it. Such strings are usually simple to manufacture and, thus, are usually the least expensive. There are several drawbacks, however:
- Roundwound strings have a bumpy surface profile (the bumps of the winding) that can produce friction when in contact with the player's fingertips. This causes squeaking sounds when the player's fingers slide over the strings. Some artists use this sound creatively.
- A non-flat, high-friction surface profile may hasten fingerboard and fret wear.
- When the core is round, the winding is not secured to the core and can rotate freely around it, especially if the winding is damaged after use.
Flatwound
Flatwound strings also have either a round or a hex core. However, the winding wire has a rounded square cross-section that has a shallower profile (in cross-section) when tightly wound. This makes for more comfortable playing, and decreased wear for frets and fretboards (this makes them a popular choice for fretless instruments). Squeaking sounds due to fingers sliding along the strings are also decreased significantly. Flatwound strings also have a longer playable life because of fewer and smaller grooves for dirt and oil to build up in.
On the other hand, players frequently cite that flatwound strings produce a less bright sound when compared to roundwounds. Flatwounds also usually cost more than roundwounds; less demand means less production and higher overhead costs; manufacturing is also more difficult as precise alignment of the flat sides of the winding must be maintained (some rotation of the winding on roundwound strings is acceptable).
[1][2]
Halfwound, ground wound, pressure wound
Halfwound strings, ground wound strings or pressure wound strings are a cross between roundwound and flatwound. Such strings are usually made by winding round wire around a round or hex core first, then polishing, grinding (thus the name, ground wound) or pressing the exterior part of the winding until it is practically flat. This results in the flat, comfortable playing feel of flatwounds, along with less squeaking, with a brightness generally between roundwounds and flatwounds. The polishing process removes almost half of the winding wire's mass, thus, to compensate for it, manufacturers use winding wire of a heavier gauge. Because of the extra manufacturing process involved they are normally more expensive than roundwounds, but less than flatwounds.
Hexcore
Hexcore strings are composed of regular
hexagonal core and a tight (usually round) winding. It prevents the winding from slipping around the core - a problem usually associated with round core strings. The hexagonal cross-section of the core provide pressure points that help secure the winding around the core better, to prevent unwanted slipping and subsequent rotation.
Metal strings offer a unique problem, as they are susceptible to
oxidation and
corrosion. Wound strings that use metals such as brass or bronze in their winding eventually corrode as moisture and salts from the player's fingers build up
oxides on the string. As a result, the string loses its brilliance over time.
[5] To help solve this problem, some string manufacturers apply a metal
plating or
polymer coating to protect the string from corrosion, and some companies sell special lubricating oils which may slow down oxidation.
Steel forms the core for almost all metal strings. Certain keyboard instruments (e.g. harpsichord) and the Gaelic harp use brass. Other natural materials such as
silk or
gut, or synthetics such as
nylon and
kevlar are also used for string cores. (Steel used for strings, called
music wire, is hardened and tempered.) Some violin E strings are gold-plated to improve tone quality.
Sheep and beef gut (called
catgut, even though cats were never used for this purpose) were the original materials used as cores for strings for
violin family instruments. Gut strings are subject to changes in humidity, which cause them go out of tune, and they also break more easily than other core materials. However, even after the introduction of metal and synthetic core materials, gut strings remain in widespread use because their warmer tone is preferable to some players. They are also desired in historically informed performances of music written before 1900. Modern gut strings are usually wrapped in metal. For players of plucked instruments, Nylgut strings are a recently developed alternative to gut strings - made from a plastic material, they offer almost exactly the same acoustic properties as gut strings, but with none of the problems of tuning caused by climatic variations. Many players of early music now use them in preference to genuine gut.
Silk was extensively used in China for
traditional Chinese musical instruments until they were replaced by metal-nylon strings in the 1950s. Only the silk strings used for the
guqin are still produced; the quality in ancient times was very high to the extent that there was a brand praised as 'ice strings' because of their smoothness and translucent appearance.
[3]
At the present time, one of the most popular materials for the cores of violin, viola, cello, and double bass strings is stranded nylon, often sold under the trade name of Perlon.
Nylon guitar strings were first developed by
Albert Augustine Strings in 1947.
[4]
Today, most jazz and folk string players prefer steel-core strings for their faster response, low cost, and tuning stability, whereas most classical string players prefer synthetic-core strings (Perlon etc.) for their richer overtones and "warmer" tone. Most baroque string players still prefer gut-core strings.
hope this helps .
