Made from spanish cedar or mahogany, it is a very important structural element. Its design is made according to the guitar players needs to satisfy their tastes. The neck is reinforced with an ebony strip in order to avoid neck bends due to the strings tension, a common problem not always considered with enough care.
The whole neck affects the sounding of the guitar. It is usually light and resistent, but if more sustain is needed it can be achieved using a more dense wood, such as mahogany and a more thick ebony fingerboard.
Neck joint and heel
They are made in one piece and integrated with top, sides and back. It constitutes to the so called Spanish heel. In the case of Fleta style guitars, the joint between neck and soundbox can be made using a dovetail system.
It is made from ebony and the frets are situated upon it. It stiffens the neck and contributes to the overall guitar sound, some known by electric guitar players but less known by some classical guitar players.
Top, bars and struts
The “engine” of the guitar. Its thickness and configuration defines the type of vibration given by the instrument and therefore, its sound.
After the first soundboard planing the properties of elastic and sound are checked for assessing which kind of guitar is appropriate.
These elements are commonly made from German spruce, Engelmann spruce, sitka o Red cedar. The bars have a structural function, while the struts command the mode vibrations of the soundboard. The struts are designed with different heights, thickness and widths related to the top properties, as well as its number and placement: fan, parallel, radial strutting, etc
Sides and back construct the soundbox. The sides are usually 1.8-2.3 mm thick and they are reinforced by any methods. Both aspects, thickness and reinforcement, affect the type of sound we want to reach out. In modern design guitars they can be made or doubled with thick laminates which avoid loss of energy and get more top vibration area, preferibly on lower vibration modes. The sides are made from the same woods as the back is, such as rosewood, padouk, mongoy, cocobolo, pau ferro, maple, walnut, sycamore, cypress, bubinga among others.
The back closes the soundbox and it can perform two different kinds of functions depending on the construction design. The first one is found in rigid boxes so that the back can behave as a sound reflector, however, in the case of the second one- lighter guitars with live backs - can perform as a sound diffusor. In this case the back should be tuned so that it vibrates out of phase with the top. The first one is found on what we call Clásico (años 60) model and Contemporáneo (Siglo XXI), while the diffusor “live” back is found on Traditional model and Flamenco models.
Nut and bridge
They are the setting points of the strings and these two pieces constitute a critical point on the tuning and playability of the instrument. Its height can influence the quality of the sound, that’s why sometimes it is necessary to make some compensation on the nut slots to mitigate any problem on tuning.
On the other hand, the correct placement of the strings on the nut and bridge slots ensures an efficient transmission of the string vibrations to the guitar. One of the common problems is that the nut slots are not wide enough and makes difficult the correct setback of the strings after they are stroked or pressed. Therefore it is very important to have the correct string fitting on the nut slots.