There are so many different strings out there: different materials, tensions, gauges, etc. Strings often have a significant impact on the sound of a guitar.
This is the conversation I had with a famous Australian guitar maker Lance Litchfield about strings, intonation and compensation methods.
L : Lance
K : Me
K : I wonder if guitar makers have any preference for strings and how they deal with this factor which can influence their guitars' sound character. Please tell us your opinion.
L : I loosely put strings into 2 categories; traditional nylon, and modern plastics (sometimes called carbon, but that refers to carbon in a compound, not element so isn’t really “carbon” in the carbon fibre sense) . Some makers may well have particular strings in mind when building, but from my perspective a guitar should be able to use any string on the market, and be complemented by them, not bound to them. Some makers do advise against modern strings as they can sometimes be higher in tension, but I don’t feel it is high enough to warrant a warning for structural reasons. Some makers recommend particular strings for their guitars, believing they are the best string available; but my feeling is that string choice is purely personal, even if there are large differences in tone and performance. The relationship between player, guitar and string is too complex to second guess.
Some characteristics I feel the two styles of strings have, in contrast to each other is that traditional strings have more warmth in tone and softer feel on the nails. They can be quite rich and sweet in tone. Talking about tone can be a little subjective however, depending on one’s ear and technique. Modern strings in general seem to have better performance characteristics with volume, dynamics and sustain. Their tone is usually focused and bright with good attack and separation. This is probably due to the higher density of the modern plastic which allows thinner gauges for similar or higher masses and tensions, which allows for less internal friction and possibly more efficiency. This has one drawback, in that some people find the higher tension combined with smaller diameter hard on nails. One benefit is that the 3rd string issues found on trad nylon are lessened, such as tuning compensation and tonal difference, which stems from a very thick diameter on the 3rd.
In my experience modern plastics are sometimes more unreliable with tuning and definitely require different compensation. This opens another topic on how to compensate a guitar, for which there are many opinions. Generally a few things make tuning harder or less consistent in my opinion. These are high action, modern plastics, and general methods of fret slotting and compensation. There are things also inherent in the guitar itself but this is another topic inside another topic!
Of course, all the other variations manufacturers do, make differences as well, so that there are a lot of choices within the two main schools. Everyone usually has a personal preference for a brand or model of string. It is also common to mix strings to get the right balance for the individual. The most common customisation I see is a modern plastic 3rd and/or 2nd string in a traditional set. It is usually to make the transition from 1st to 4th string tonally more consistent. Quite often people can also find the modern 1st strings a little too tinny or sharp or harsh in tone, and this is sometimes substituted with a trad nylon. Some strings last longer than others, some cheaper, some more readily accessible, and all of that influences string use too.
K : Why do you think modern plastics are sometimes more unreliable with tuning?
L : I am not a chemist or physicist, so I can only guess as to why they may be less reliable. It is just something I have noticed in my dealings with modern plastics in relation to my style of setup, which is primarily a higher concert action with attention to intonation. The only thing I can imagine that may influence tuning of the strings is that smaller diameters and higher densities require slightly higher tolerances. This may just lessen the amount of control the manufacturer has. It could be that higher tolerances are less forgiving and perhaps this makes it more susceptible to wear and damage and manufacture irregularities. On the whole they are very good, but at the fine end of tuning error I feel they are a little less forgiving, between sets. They certainly show consistent tuning traits as a type of string in general (between models of strings, rather than same type of sets).
K : Please tell us about intonation and compensation methods.
L : There are a lot of factors that go into setting up a guitar to have optimal tuning. These are primarily nut and saddle position, fret position accuracy, and action height. String type also has an impact on tuning regarding the consistency and compensation needed. There are other factors which appear mainly at the fine end of tuning work, like inherent traits of a particular guitars (can sometimes be quite marked). These can be related to inherent resonances of the guitar that can interfere with the pitch of the note plucked. Other issues can be related to modern equal temperament tuning, and instruments that change pitch easily with less than precise fretting pressure. Guitars that have more sustain and richer sound can also open more possibilities for notes and harmonics to overlap in comparison to percussive and separated guitars.
Most of the latter points are smaller priority than the former, but can interfere with intonation, especially when one requires certain intervals to be issue free, like octaves and fifths between strings. The little errors can add up in unfortunate ways and the luthier may need to work hard to minimise this. These little errors can also be hidden in the variances in strings and player technique making it a little harder to decipher, and so luthiers will usually prefer to standardise as much as they can if tuning is a particular concern for the client. In my case I ask the client to stick to a particular action height, string brand and model, if I need to attend to tuning issues. Usually for my guitars, I compensate each string at the nut and saddle although there is usually no need to go to these lengths for flamenco guitars due to the low action and different demands in the genre.
There can be a lot of reasons for favouring a high action. Personally for concert guitars I prefer to set action high, but it is ultimately a personal thing and I am happy to set action to whatever the client wishes. Everyone has different requirements, but in general if a client plays hard and wants minimal fret buzz a high action is a good idea. Some guitars feel tighter than others and high action on those guitars may not be as easy as others. This can be related to the design and materials of the top, and also the age of the guitar in my opinion. Of course, older guitars can often have high action if the set of the neck changes over time, but that is another story. Lightly built guitars can sometimes have neck set issues, and most of the time I see this on old flamenco guitars.