What determines how hard it is to press a guitar string?

Question

When playing on different steel string acoustic guitars over the years, I noticed a huge difference in how hard it was to press down a string. This made me wonder why.

There are two obvious factors that come into play: thickness of the strings and the action of the instrument. I guess length of the neck also plays a role, however probably a minor one.

My question now is: are there more things about a guitar that influence how hard it is to press down the strings? Some things that I overlooked? And when looking for an instrument that is the easiest to play, what should I look for in particular?

Answer 1

• String tension is probably the most important factor, dictated by the gauge and tuning mainly.

• The action will affect how hard or easy the strings are to press, as a high action means further to move.

• The neck itself will have some bearing on this as a deep neck uses up more of your hand thus grip. A thin neck - both back to front and side to side, will make pressing easier.

• Even how you hold the guitar will affect pressure. The fingerboard angle, both to vertical and horizontal, will make a difference. Although if that attitude is the same for different guitars, you will have a direct comparison.

• As you state, two guitars with different scale necks but the same gauge strings will need different pressures.

• The relief in the neck- related to action- will affect pressure at different points on the neck. A closer to the fingerboard string at fret 2 will be different to press than the same string at fret 12. The tension is the same, but the distance to press may be a factor of 2 or 3.

• A cambered fingerboard will probably be easier to play than a flat one.

Answer 2

If we read "how hard" as meaning "how much force is required to push the string far enough onto the fret that it sounds cleanly", then there are only two factors:

• The tension of the string
• The distance the string has to move - that is, the action.

The tension is itself a factor of three variables:

• the length of the string (longer = more tension, for the same pitch and gauge)
• the gauge of the string (heavier = more tension, for the same pitch and length)
• the pitch of the string (higher pitch = more tension, for the same length and gauge)

So, if you want "easier" fretting, one or more of:

• lower the action
• use lighter strings
• tune down
• use an instrument with a shorter scale

However, lower tension has some disadvantages - flabbier sound, fret buzz, easy to bend accidentally.

One further factor is the wideness of the string. A very narrow string bites into your finger. A wider string distributes the force across more surface area. If two strings have the same tension, but one is thicker, the thicker one is likely to be more comfortable to press down. There may be cases where a wider string, despite needing more force to press down, is more comfortable for the finger because of its width.

Answer 3

Your own findings are correct. The action is the most important factor, and thickness as well to a lesser extent.

Another noteworthy factor is the tension of the string. You'll notice that a string takes a bit more force to press down if its tension is higher.

Answer 4

Theory notwithstanding, nearly all guitars have the same scale length, and string weights are limited to about three choices, and action has constraints limiting how low you can get it. So, in the real world we have to make some trade-offs.

Many acoustic players prefer medium action, not low. Lower the action to the cusp of buzzing, and you will limit the volume and the kinds of playing you can do without causing it to buzz. It's a trade-off. If you want really easy-to-play guitar, get an electric. On an acoustic, the goal is not to have it be super-easy to play so much as having it not be particularly difficult. A very low action will limit your dynamic range by limiting how much room the string has to vibrate -- not a big deal in some situations, especially when plugged in, but still. Talk to someone who has been playing twenty years, and super-low-action is not likely to be on their shopping list.

There is one more thing that ought to be mentioned: the quality and condition of the fretwork. We have so far assumed that the frets are all basically level with one another and are unworn. If this is not the case, it can cause buzzes even with not-too-low action.

Part of this is the curvature of the neck, and part of it is the leveling of the frets. This is normally a non-issue on all but the cheapest new guitars, but if you buy secondhand you need to look for places where the frets have worn down. That, and "sight" the neck (put your eye over the bridge and look toward the headstock, slowly tilting the guitar backward and watching the frets converge. From this angle you'll see if the frets all settle evenly behind one another, or if whole groups of them disappear behind one another (which would indicate you've got trouble.)

Note also that the action at the nut end is just as important as the action at the bridge end. If the bridge end is too high, it will be a bit tough to play but you'll get good tone and it will be forgiving of exuberant playing styles. If the nut is too high, it will be hard to play and, well, it will just suck.

So, in the end, get a decent guitar and have it set up professionally. Show the guitar to your setup guy before pulling the trigger, and make sure he says it will come out okay. He will know in a minute, just by looking it over.

If a professionally set up good quality guitar in decent condition is too hard to play, then keep playing until it isn't hard anymore.

Answer 5

I can't believe no other answers your final and most important question with any detail!

And when looking for an instrument that is the easiest to play, what should i look for in particular?

You shouldn't look solely for an acoustic guitar that is easy to play.

The play-ability of an acoustic guitar is the only thing that can be easily adjusted!

Nearly all mass produced retail guitars (including very expensive ones) are set-up terribly from the factory and benefit greatly by a set-up from a good luthier. Any guitar, cheap or expensive, can be made to play very well provided it doesn't have any serious defects (eg warped neck, uneven frets) in which case you can return the guitar to the shop.

Buy a guitar you like the look and sound of. These are the properties that cannot be altered easily. Get it set-up by a good luthier to match your specific needs, it will be easier to play and sound even better. (see here for more info: Will a more expensive electric guitar be more consistently harmonious? )

My question now is: are there more things about a guitar that influence how hard it is to press down the strings? Some things that i overlooked?

This question is analogous to a combination of a simple beam deflection problem found in all engineering mechanics textbooks and the backpack on a cable problem found in 100 level physics texts. If you want a complete answer try physics stack exchange, All of the current answers are missing key variables. (from my comment).

This is really beyond the scope of this website but I will try to explain the basics in lay-mans terms.

A vibrating string is a physical system. Different strings (even of the same gauge) sound different because they have different material properties. The same material properties that affect (the sound of) vibration affect how it acts under other forces such as a point load (ie fretting pressure). The main properties are stiffness and density, these properties form the specific modulus. Stiffness affects force required for deflection, density affects mass per length of the string (a value in the frequency of vibration (pitch) of a string equation).

http://en.wikipedia.org/wiki/Elastic_modulus

http://en.wikipedia.org/wiki/Specific_modulus

For a given mass per length a less dense string will have a greater area moment of inertia which affects deflection.

http://en.wikipedia.org/wiki/Area_moment_of_inertia

Which brings me to the other factor: Which fret you are fretting-

Compare the equations for a centre loaded beam and an intermediately loaded beam here:

http://en.wikipedia.org/wiki/Deflection_(engineering)#Center_loaded_beam

As a given force is moved from the mid point to the anchor points the deflection decreases. Or in other words, the force required to fret increases nearer the anchor points (the nut and bridge). This can be demonstrated easily by bending (which like fretting, requires deflection of the string or 'beam'): Try a whole step bend at the 12th fret (mid point) and then at the first or second fret, the required force is vastly different.

There are other less important points which I've left out. If you want to understand this problem completely I suggest you do a physics or mechanical engineering degree ;-)

Answer 6

There's also what the string is made of. Usually nylon is really easy to press down on regardless of string thickness, but steel kills your fingers.

Answer 7

I was never able to play guitar because of how hard it was for my fingers to correctly hit that neck, I discovered a Keith urban guitar and the steel strings were very close to the neck,,and I promise, that helped my delicately fingers play without cramping and making my fingers sore. I'm not sure the correct term for it, but maybe if u ask a professional, they will definitely know where to steer you

Answer 8

Sorry all these answers are pretty much BS, its the action that's the end of it. When did you last get a tension meter out to see how a instrument feels. Lower gauge strings will help , but not that much, a thinner string will cut your fingers up if played a lot. After all quality is what you paying for on more expensive guitars, the wood and frets are harder and last longer and the action is tighter. If you have a reasonable quality instrument the action will improve as it wears in, I have a Yahama that is 40 years old and has had good use and the action is very smooth. I have another guitar of similar age, but inferior quality and the action is awful, and a complete bitch to play.

The other thing I don't think you have stopped to consider is the width of the neck as a narrow neck can make guitar with great action awkward to play, if the strings are close together it makes it suitable for only certain types of music and is partly the reason I prefer to practise on a classical guitar.