The acoustic guitar bridge is that part of the instrument that lies on the harmonic case, below the hole, with the function to keep the strings anchored on it.
But the bridge is not only necessary to keep the strings fixed on the board, it also has the function of transmitting their vibration to the instrument body through the bone.
Materials for the guitar bridge
Usually, the acoustic guitar bridge is made up of wood.
The variety of wood you choose is very important because, how I said before, the bridge has to conduct the vibrations to the harmonic case: this energy passage must be as efficient as possible.
This means the goal of a good bridge is to transfer as much of energy as possible with a minimum dispersion. Hard and thick woods are needed to achieve this. More flexible and soft woods would instead allow too much energetic dispersion during its transmission and this is harmful.
The most commonly used woods for building bridges are rosewood and ebony. Both are very tough and have a sufficient density to ensure a good vibration propagation and also have a good balance between hardness, density, and lightness.
The choice of the wood kind to use is often influenced by aesthetics, to ensure a certain continuity in the design and in the materials that make up the bridge, the keyboard, and the bands. In any case, during the realization of this guitar component, all of the key parameters must be considered to have an aesthetically good result combined with functionality and strength.
Strength is a further parameter to keep in mind. The stress on the bridge is remarkable, so it has to be made up of robust and resistant materials.
Acoustic guitar bridge models
There are two types of acoustic guitar bridge: fixed, generally mounted on both classical and folk guitars, and floating, usually equipped with the arched and semi-acoustic guitars.
The fixed bridge is glued directly to the case with the strings anchored on it. These are fixed to the pegs, which are similar to wooden or plastic pins inserted into special holes on the bridge.
The string is inserted into one of this holes and, when it is tensed, it is blocked by the pressure of the peg.
In the classical guitar, however, the strings are knotted to the bridge, but the nylon strings have less tension so they make less pressure on both the bridge and the guitar shovel.
In the floating bridge, the strings are anchored to a fixed tailpiece, and you can adjust the instrument pitch by moving the jumper where the strings lie.
There are also other guitar models, such as the Ovation, which has a grooved fixed bridge in which the strings are not inserted into the holes and not held in place by the pegs, but instead, they pass horizontally into the bridge and are fixed by positioning some little balls in dedicates spaces.
The bridge bone lies in a groove drawn on the bridge and above it, there are the strings, which transmit their vibrations here. Usually, the bone has a fixed height, but there are models where it can be adjusted via screws.
Guitar bridge maintenance
Acoustic guitar bridge should be maintained and kept in order as the whole instrument to preserve its duration and to keep unaltered its sound characteristics.
To remove dust or any residual dirt from the bridge, you can use a soft and dry brush to gently clean this piece.
More thorough cleaning can be performed while replacing the strings using a dry soft cloth and, if necessary, specific detergents or oils depending on the bridge material.
Regarding its regulation, the bridge has its importance in determining guitar action.
To replace the bridge, both in case of damage and if you want to equip your own guitar with a different one, the golden rule is to contact an expert lutist.
While other simpler operations can also be done in DIY mode, it is preferable to delegate to a professional all the work on the bridge: in addition to being a fundamental part for sound diffusion, this component is positioned on the harmonic case that also has a crucial importance.
The case is normally subjected to the tension of the strings, and cracks and injuries caused by an inexperienced hand can become worse by compromising the sound quality; it is also a piece often decorated with paints or polished to show the wood grain and it you have to avoid to scratch it and to ruin its aesthetics.
[Photo credits: Henry Zbyszynski]
ALWAYS IN TUNE!