Finding the right string height or action for your violin can be a delicate process: a balancing act between the standard measurements that are used by luthiers, the unique characteristics of the violin in question, the strings being used, and the particular tastes of the musician. Once addressed and correctly set up though, the action on a stringed instrument can have an enormous effect on not only the playability and comfort of the instrument, but also the sound.
On the fingerboard of a stringed instrument, there is a lengthwise concave curvature that is commonly referred to as the ‘scoop’. The amount of curvature to the scoop may depend on the types of strings being used by the musician, with gut strings having wider vibration and requiring a deeper curvature, steel strings not requiring as deep a scoop, and synthetic strings lying roughly between the two.
The scoop of the fingerboard is only one factor influencing string height however. The height and shape of the bridge as well as the correct tension on the strings need to be considered in setting a string height that is uniform across the whole fingerboard.
But why is string height so important for the sound of an instrument? It may at first appear that it can’t have that much of an impact, and getting the right string height is not going to magically lead to the best sounding instrument out there. However, a millimetres difference in the action can not only make the violin difficult and possibly harmful to play in the long-term, but a correct string height may increase the playability of the instrument, facilitate better intonation, greater projection, and most importantly, make you feel much more comfortable playing your instrument.