Anatomy of the String Bass

The string bass is also known as the double bass, upright bass or bass violin. Today's basses are made from woods such as beech, poplar, pine and cedar. Earlier basses were made of spruce and maple. It is similar to an oversized cello with more sloping shoulders on top and is also played with a bow or by plucking the strings. But the sound produced by the string bass is like no other in the world.

To be the best you can be at playing the string bass, you should know all the common names of the parts of the string bass and what function they perform. You should also know how individual string bass parts can be removed and replaced, how string bass parts should be serviced and maintained and what to do if you think a part of your string bass is damaged or broken.

Let's learn about the anatomy of a typical string bass from end to end. If you'd like to jump ahead, use the anatomy chart above to click a part you'd like to read about first.

 

WHAT IS THE BASS BAR?

This is a strip of seasoned spruce hidden inside the string bass that has a large effect on the its bass tone and lower register.

The bass bar is a thin strip of seasoned spruce, mounted in a standing up position under the left side of the top. It is mounted in line with the strings and reaches almost from one end of the string bass's body to the other.

The bass bar shapes the waves of vibration inside the string bass to produce deeper, more resonant bass tones.


Click to return to anatomy chart



WHAT ARE THE BOUTS AND WAIST?

The string bass is shaped with attractive bouts and a waist that maximize sound production and make room for the bow.

The terms "bouts" and "waist" or "c-bouts" describe various parts of the string bass body's eye-catching shape. When the instrument is held in playing position, the waist or c-bouts are the cinched-in areas in the middle. They are cut out of the curve of the wood of the top along its edge. This allows the bow to move across the strings at a variety of extreme angles without hitting the side of the body.

Above the waist are found two upper bouts and below are two lower bouts. The hourglass shape made by the bouts makes the string bass recognizable instantly by the player and non-player alike.

Players will notice that the upper bouts of the string bass slope much more quickly than those of the other members of the stringed instrument family. This is because the sheer size of the string bass would make it next to impossible for the player to reach around and access all its functionality without this design.


Click to return to anatomy chart



WHAT IS THE BRIDGE?

The bridge is a small piece of maple that holds the strings away from the top of the string bass and transfers vibration to the body.

The bridge is a small, decoratively-carved piece of maple that is positioned on the top between f-hole notches. Its function is to and hold the strings away from the string bass's top surface. This allows the strings to vibrate freely while transferring that vibration to the resonant cavity of the body. It also provides a spacer between the strings so they rest evenly above the string bass's fingerboard. The bridge is not permanently attached to the string bass but holds its position securely under the strong tension of the strings.

The height of the bridge can be adjusted within the standard specifications to suit the playing style of the player.


Click to return to anatomy chart



WHAT IS THE END BUTTON?

The end button holds the string bass's tail gut and tailpiece firmly in place.

The end button is found at the end or bottom of the string bass body and is usually made from a hardwood like ebony or rosewood. The tail gut of the modern string bass attaches at the end of the tailpiece and loops around the end button so it has a secure anchor point to hold the tailpiece in place.


Click to return to anatomy chart



WHAT ARE THE F-HOLES?

F-holes help shape and direct the sound of the string bass.

F-holes are openings carved into the top of the string bass that act to increase the power of the tone emitted by the instrument. They allow some sound from the resonant interior of the string bass to escape to the listener, but that is not their primary purpose. In fact, most of the tone provided by the string bass comes from the vibration of the top and the back transferred directly to the air.

Over the centuries, instrument makers have tinkered continuously with the placement, size and effect of sound holes on stringed instruments. Acoustical testing has shown that they allow more freedom of movement between the top and back. They also help focus sound production, affecting the tone quality in a way that is much more impactful than just allowing sound waves to escape.


Click to return to anatomy chart



WHAT ARE THE FINE TUNERS?

Fine tuners allow for more precise tuning of each string.

Fine tuners are rare for string basses, because the innovation of machine heads for tuning has made them virtually unneccesary. However, they can be found for all or some of the strings on the tailpiece of the string bass, most commonly on the E string. However, some instruments have fine tuners installed for all four strings.

The fine tuning is done by a small lever that is adjusted by a small thumb screw. Fine tuners can either be individual pieces that are affixed to the tailpiece at the end of each string or they are built-in to the actual tailpiece.


Click to return to anatomy chart



WHAT IS THE FINGERBOARD?

The fingerboard provides a hard surface for the string to be pressed down onto so notes can be played.

String bass fingerboards are mostly made of ebony, a very hard black wood. Other hardwoods are sometimes used on lower quality instruments and are blackened to look like ebony.

The string bass fingerboard does not have frets like a guitar to delineate one pitch from another, so the player must have a strong ear and sense of pitch to play confidently in tune.


Click to return to anatomy chart



WHAT ARE THE MACHINE HEADS?

The machine heads are made of metal and are used to adjust the pitch of each string easily.

The string bass is the only member of the traditional stringed instrument family to have metal machine tuners, which are necessary due to the remarkable force exerted by the string bass's larger gauge strings.


Click to return to anatomy chart



WHAT IS THE NECK?

The neck extends from the body to hold the strings and fingerboard.

The neck is an extension of the body of the string bass that holds the strings and fingerboard and ends at the pegbox & scroll. It is typically carved from sturdy maple.


Click to return to anatomy chart



WHAT IS THE NUT?

The nut (or string nut) holds and directs the strings down the fingerboard to the tailpiece.

The nut is found at the top end of the fingerboard, holding the strings in perfect alignment and exact height from the fingerboard to maximize the string bass's tone and playability. Four small grooves or notches are carved into the top of the nut, into which the strings are placed before winding around the pegs.


Click to return to anatomy chart



WHAT IS THE PEGBOX?

The pegbox holds sturdy tuning machines for the strings to wrap around so they can be tuned.

The other end of the strings is anchored at the tailpiece. Each peg is slightly tapered in shape, allowing the player to adjust the hold of the peg by applying more or less pressure and turning. Often, the pegbox and the scroll of the string bass are carved out of a single piece of wood.

To make the pitch of the string higher, the tuners are twisted to tighten the tension of the string. A looser tension results in a lower pitch.


Click to return to anatomy chart



WHAT IS THE PURFLING?

The decorative edge adds visual appeal and keeps the string bass from developing cracks.

Around the edge of the top and back are seen a decorative edging known as "purfling." This inlay has decorative appeal and also helps reduce the chance of cracks developing in the string bass's top and back.


Click to return to anatomy chart



WHAT ARE THE RIBS?

The ribs (or sides) are carefully crafted to hold the string bass's top and back apart, creating the space for the sound to develop.

The string bass's ribs (or sides) are the wood pieces that run around the entire outer edge of the string bass body, between the top and back. The ribs hold the two pieces apart, creating the resonant cavity that produces the string bass's sound.


Click to return to anatomy chart



WHAT IS THE SADDLE?

The saddle helps spread the force of string tension away from the string bass's center toward the chin rest.

A string bass saddle is a small rectangular block of wood, often crafted of ebony, which helps relieve pressure exerted on the string bass's body by the force of the string tension.

It is found at the end of the string bass and supports the tailgut.


Click to return to anatomy chart



WHAT IS THE SCROLL?

The scroll is a decorative carved wood piece at the end of the string bass.

The scroll is a decorative carved wood piece at the end of the string bass, usually carved out of the same piece of wood forming the pegbox. The most common carving is a delicate scroll shape knows as a "volute" that dates back to the Baroque period.


Click to return to anatomy chart



WHAT IS THE SOUND POST?

The sound post bridges the insides of the top and back of the string bass, allowing them to vibrate in unison for a stronger sound.

The sound post of a string bass is a small cylindrically-shaped piece of wood (usually made of spruce) that is positioned inside the string bass with the tip touching just below the right foot of the bridge. It runs between the top and back of the string bass, transferring vibration from one surface to the other to maximize the tone of the string bass. This simple invention greatly increased the resonance of the string bass when it was discovered.


Click to return to anatomy chart



WHAT IS THE SPIKE?

The spike is a thin piece of metal that supports the string bass during playing.

Before playing, the spike is fitted into the end button and tightened at the desired height with a small screw. This allows the instrument to be adjusted to any height of player or preferred playing position.


Click to return to anatomy chart



WHAT ARE THE STRINGS?

The strings vibrate and transfer that vibration to the body for amplification and resonance.

There are four strings on the standard string bass, typically tuned to G, D, A and E. The G is the lowest in pitch. The player works a horsehair bow across the strings or plucks them while fingering notes on the fingerboard to produce chords, single notes and other sound effects.

The classic string is made of sheep's gut, though very few strings are made of this material today.

Every player has differing opinions on how often the strings should be changed. However, when a string snaps or loses the ability to stay in tune or produce a pleasing tone, it should be replaced.


Click to return to anatomy chart



WHAT IS THE TAIL GUT?

The tail gut holds the string bass's tailpiece to the end button.

The tail gut of a modern string bass is threaded at either end and attached to the tailpiece with a small adjustment screw. These important pieces are made of both metal and nylon materials today, though traditionally they were crafted from twisted strips of animal intestine.

The precise adjustment of the tail gut has a major effect on the sound quality and tone of the string bass, and it may require occassional adjustment when it is new. Over time, the string bass's tail gut will settle and not need as much attention.


Click to return to anatomy chart



WHAT IS THE TAILPIECE?

The tailpiece holds the strings to the body of the string bass on its lower end.

The tailpiece is the anchor holding the strings to the body of the string bass on its lower end. Unlike most of the other parts of the string bass, the tailpiece is held to the string bass strictly by string tension.

Many instruments have an individual fine tuner on the tailpiece for at least the E string, if not for all the strings. Some tailpieces have built-in fine tuners on the tailpiece for all the strings. The tailpiece can be made of several types of wood or composite material and is seen in other wood colors besides the typical black.


Click to return to anatomy chart



WHAT ARE THE TOP AND BACK?

The top and back of the string bass resonate to provide tone and volume.

The string bass's body is constructed of two large, arched pieces of single wood that are held apart by the ribs. When the string bass is resting on its back, the soundboard or "top" is seen on top with two distinctive "f-holes" cut through. The back is one large wide area of resonating wood without any hole seen anywhere.

The quality and age of wood in the top and back of the string bass have a large impact on its sound. String basses are very subject to their environment, including heat and humidity, but a well-made, well-cared-for, frequently played string bass will improve markedly with age. The varnish's age, type and condition will also affect the sound perceptibly.

Today's basses are made from woods such as beech, poplar, pine and cedar. Earlier basses were made of spruce and maple. Around the edge of the top and back of the string bass is seen a decorative edging known as "purfling." This inlay has plenty of decorative appeal and also helps lower the chance of cracks developing in the top and back.


Click to return to anatomy chart