Guitar String Construction – How They’re Made
Depending on the construction of the instrument on which they are used, strings will usually have either a ball or loop at one end to attach the string to the instrument. Strings for some instruments may be wrapped with silk at their ends to protect the string. The color and pattern of the silk can be used to identify the string.
Winding There are several varieties of wound strings.
The simplest ones are the roundwound strings. They have a round core inside and round-winding 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 surface profile (the “bumps” of the winding) that causes “squeaking” sounds when the player’s fingers slide over the strings. Whereas some artists use this sound creatively on purpose, this sound is, in general, unwanted.
- Non-flat surface profile also hastens fingerboard and fret wire wear.
- The winding is not secured to the core and can rotate freely around it, especially if the winding is damaged after use. It makes it harder to push down and hold the strings with the fingers, and thus impairs the general playing experience.
Flatwound strings also have a round core, but the winding wire has a rounded square cross-section. When tightly wound, such strings have a much shallower profile (in cross-section), thus making them more comfortable to play, less damaging for frets / fretboard and producing quieter squeak sounds from fingers sliding along the string. However, players frequently cite that the sound of flatwound strings differs considerably from the sound of roundwound, with less brightness.
Halfwound, ground wound, pressure wound
Halfwound strings, ground wound strings or pressure wound strings are a cross between roundwound and flatwound, providing both the tonal characteristics of roundwound and the lack of squeaking and the playing feel of flatwound. Such strings are usually made by winding round wire around a round core first, then polishing, grinding (thus the name, ground wound) or pressing the exterior part of the winding until it is practically flat.
Note that polishing process removes almost half of winding wire mass, thus, to compensate for it, manufacturers have to use heavier gauge winding wire. In its turn, thicker winding wire lowers frequency of slide squeaking. Depending on sound processing, it can be a good thing (as squeaking becomes less accented and it will be masked out by performed music) or a bad thing (high-pitched squeaks are much easier to detect and filter out when recording).
Hexwound strings are composed of regular hexagonal core and a tight (usually round) winding that closely fits a hexagonal shape. It solves the second problem: it secures the winding around the core, so it cannot rotate and slip under the fingers. Sometimes it is cited that hexagonal core improves tones due to closer bond between the core and the winding The drawback is that relatively sharp hexagonal corners are less comfortable for fingers and wear down the fingerboard and fret wire even faster than roundwound strings. Hexwound strings are more commonly used on bass instruments (such as bass guitars).
The tone of a string depends on its weight, and, therefore, on its diameter or so-called gauge. Traditionally, diameter is measured in thousandths of an inch. The larger the diameter, the heavier the string is. Heavier strings require more tension for the same pitch and are, as a consequence, harder to press down to the fingerboard. Heavier strings will also produce a louder and thicker tone. (If a fretted instrument is restrung with different string gauges, it may be necessary to adjust the height of the string above the frets, called the “action,” in order to make the instrument easier to play or to avoid the strings buzzing against the frets. The action height of fretless instruments may also be adjusted to suit the string gauge or material, as well as the intended playing style.)
Steel strings for 6-string guitar usually come in the sets of matched strings. Sets are usually referenced either by the gauge of the first string (e.g., 9), or by pair of first and last (e.g., 9-42). Some manufacturers may have slightly different gauge sequences; the sample data below comes from D’Addario string charts for regular, round-wound, nickel-plated strings.
(Note: strings in gray boxes are wound. All others are plain.)
|Extra super light (8-38)||.008||.010||.015||.021||.030||.038|
|Extra super light plus (8.5-39)||.0085||.0105||.015||.022||.032||.039|
|Super light (9-42)||.009||.011||.016||.024||.032||.042|
|Super light plus (9.5-44)||.0095||.0115||.016||.024||.034||.044|
|Regular light (10-46)||.010||.013||.017||.026||.036||.046|
|Extra light w/heavy bass (9-46)||.009||.013||.021||.029||.036||.046|
|Medium w/wound G string (11-52)||.011||.013||.020||.030||.042||.052|
|Extra heavy (13-56)||.013||.017||.026||.036||.046||.056|
These are the frequencies that guitar strings vibrate: E-82 Hz, A-110 Hz, D-147 Hz, G-196 Hz, B-247 Hz, E 330 Hz.