Elements such as the top, construction or frets influence the hardness
Many times a guitar is described alluding to its level of hardness, but:
What exactly is the hardness?
The hardness in the guitar is the sensation of tension in the strings, both in the pulsation of the right hand and in the pressure made by the left hand.
Is discomfort the same?
A very hard or very soft guitar is negative. These extremes make a guitar uncomfortable and difficult to play. Guitars in which is difficult to apply certain techniques, especially, when we speak of a "virtuous" performance.
In fact, the ideal guitar is that which the degree of hardness depends on the style and needs of the guitarist.
What part is responsible for making a hard guitar?
Several factors contribute to make a harder guitar. The thickness of the lid or its structure of harmonic bars, the scale or even the environmental dryness. These elements directly affect the tension of the strings.
Factors that affect the tension in the strings
In this topic it is necessary to talk about the scale of the guitar, the distance between the saddle and the nut.
The most common scale in the guitars is 650 mm, although we can find 655, 660 or even 664 mm for the larger hands or guitarists who feel more comfortable with these measures.
On the contrary, for guitarists with the smallest hands, we can find guitars of shorter scale, 640 or 630 mm.
If we compare two guitars with the same type of strings, with a different scale but similar construction, in terms of bracing and thickness of the wood in the top, we find that the hardness between the two changes.
The result will be that the guitar with longer scale will be harder because to obtain the correct tuning, the strings exert greater tension in the guitar with longer scale.
It is important to note that the tension of the strings acts directly on the bridge. Specifically a small deformation occurs in the area of the lower top, under of the bridge. For this reason, when more rigidity is in the top, less deformation occurs and more tension is created in the cords, which means greater hardness.
In the same way, the environmental dryness contracts the wood and reduces the flexibility of the top, reducing the small deformation of the top in the bridge, so that to maintain the tuning the tension in the strings is superior.
In these cases, when the hardness of the instrument does not please the guitarist, the solution can be the change by strings of lower tension.
About the sound
We must not forget that with nylon strings, excessive tension will not break the guitar, but if there is a lot of rigidity in the top, the vibration of the top will decrease and the duration and quality of the sound will also decrease. It may even happen that you get more projection but less amount of sound.
When we put strings of less tension in very hard guitars, the top loses rigidity and contributes to balance the guitar.
An extreme example would be a long scale guitar, with a thick top, a high bracing (many harmonic bars) and high-tension strings. The result would be a very difficult instrument to play with a lot of tension on the strings.
A long scale was considered better in the past because more sound was obtained by the increase in the vibration of the strings, although in fact the type of construction is much more important than the scale of the guitar.
As we have said, there are other factors related to the hardness through the comfort of the instrument.
To be able to play, an excessively high action requires more pressure in the left hand. Something similar happens if the frets are low, because you have to exert more force to get the guitar does not tune and sounds good.
Regarding the neck, if it is thick it complicates the movements in the left hand, so that a thin neck improves the comfort in the interpretation.
A large number of Alhambra Guitar models incorporate the "ergoneck", a design to offer greater comfort to the performer while maintaining the stability of the instrument.