String Tension 101
In our previous blog, we gave a brief introduction to the world of string gauges. We discussed how gauge can affect the playability of a guitar and we also touched on the concept of string tension too. In this blog we’re going to delve a little deeper into tension, talk about its close link with string gauge and why it’s something you should also be conscious of.
Tension is something that is more commonly referred to when we talk about classical guitar strings. However, when we discuss other types of guitar strings such as electric, acoustic and bass strings, string gauge is more prevalent; and in most instances the technical information on each individual string’s tension isn’t something that all manufacturers freely provide. D’Addario are one of the few manufacturers that list both and for this reason we will make reference to their string tensions throughout this blog. If you wished to take a look at their tension chart for yourself, you can do so by following the link at the bottom of the blog.
Right, so let’s get started….
In essence, every string will exert a certain amount of tension on a guitar when it is strung up. How much tension exactly will depend on three main factors;
The Tension Triangle above has a factor at each corner. Changing one of these factors will directly affect the amount of tension in the string. Below we’ll take a look at each factor in turn.
So first up is our old friend string gauge. As we learnt previously, the higher the gauge, the thicker the string. This is generally true for tension too. Typically you’ll find that the thicker the gauge of the string, the more tension it has when tuned to pitch.
For example, if we were to take a Telecaster strung with 10-46 gauge strings, we’d find that if the strings were changed to a heavier gauge (let’s say 11-49 gauge), the tension exerted by each string will increase. As a result of this increased tension, the new set will “feel” stiffer, the top strings will require more effort to bend and some players who prefer a lighter gauge may say the set feels “harder” to play.
This works the other way too. If we were to string the same Telecaster up with 9-42 gauge strings, we’d find the tension will be lighter than that of the 10-46 set.
This is all pretty self explanatory stuff, but apart from string gauge, how much tension a string exerts will depend on the other two factors.
Pitch basically refers to whichever note we are tuning the string to.
So if we take our Telecaster example again, this time we’ll reference the low E-string. The .046” gauge string will exert 17.5lbs of tension when tuned to a standard E note. However, if we decided to tune our Telecaster down to drop D, we would need to lower the pitch of the ‘Low E’ a whole step down to ‘D’ and in turn we would be reducing the tension too. So our .046” string when tuned to D will now have just 13.9lbs (as opposed to our 17.5lbs when tuned to E). In real terms this will make the string feel ‘looser’.
Likewise if we were to go the other way and tune the E up to F, the tension would increase too. A .046” tuned to F would raise the tension to 19.6lbs (instead of 17.5lbs when tuned to E).
If you’ve ever decided to get your ‘Jimi’ on and tune your guitar down to Eb (where all 6 strings have been tuned-down by half a step to Eb, Ab, Db, Gb, Bb, Eb) you will have noticed that your strings felt a bit looser and somewhat easier and more ‘buttery’ to play. If you haven’t tried it before, give it a go, it feels good!! Some players will tune their guitars down half a step on a regular basis and it’s a common thing to do in certain styles of music such as blues-rock.
So from what we’ve learnt so far, if we wanted to detune our guitar and have it in Eb the whole time, but didn’t really like the “looser” feel of our strings when tuned this way, what we could do is go up a gauge (heavier gauge) to compensate for the drop in tension. With this in mind we could opt for an 11-49 set. The 11-49 set will usually have more tension when in standard tuning. However, because we’ve tuned down to Eb, this will lower the tension of this heavier gauge set. Hope that makes sense!
Scale Length is the final part of our tension triangle. So far we have seen how the tension of our strings change depending on the gauges that we use and also what pitch our strings are tuned to. We’ve been using the Telecaster strung with 10-46 gauge strings as our example, but what if we put these strings on a different guitar? And what if this new guitar had a different scale length?
What’s a scale length we hear you ask?
This is the distance (usually measured in inches) from the fretboard edge of the nut down to where the string makes contact with the saddle. You may also find people INCORRECTLY refer to this as the “speaking length” of the string too.
You may or may not be aware that different guitars can have different scale lengths. For example, Fender guitars such as the Stratocaster and Telecaster have a scale length of 25.5”, whereas PRS guitars have a shorter scale length of 25” and Gibson guitars have a shorter scale length still of 24.75”. Even shorter is the dinky Fender Mustang coming in with a 24” scale length. Cute!!
Bass guitars are a very good example of this too. They come in a variety of scale lengths; short, medium, long (standard) and extra-long scale. As you will have guessed, the scale length increases as you progress from short scale basses up to extra-long scale. So what exactly does this mean for the tension of our strings?
As a rule of thumb, the same gauge string tuned to the same pitch will increase in tension as the scale length increases.
So using bass guitars as an example, if we take a .105” gauge string tuned as our Low E, the tension in the string will vary according to what scale length bass it’s fitted to. See below;
Short Scale – .34.0lbs
Medium Scale – 35.7lbs
Long Scale – 40.3lbs
Extra Long Scale – 45.2lbs
As you can see for the exact same string gauge, tuned to the exact same pitch, the tension varies depending on the scale length of the instrument.
Balanced Tension String Sets
If you’re up to date with your string trends you may well have noticed manufacturers have started to make sets with more ‘balanced’ string gauges across the whole set.
Most manufacturers make their sets with tried and tested gauges that appear to have been around since the dawn of time. There has been little deviation from these gauges and limited questioning to whether these gauges are actually in balance with each other?
The problem with the tensions of these strings is that they can be quite varied from one string to the other, even within the same set. Imagine bending your high E string and then bending your B string..the amount of effort required to bend the High E could be wildly different to that of the B-string if the two tensions are not in sync with each other. If you carry this across the whole set, you can find that all the strings in the same set vary quite drastically.
In light of this, some manufacturers have started to produce sets where the tension is more equal across all strings in a bid to help make the set feel more comfortable and consistent in it’s playability.
Lower tension sets
There are also some manufacturers that produce purpose made ‘lower tension’ guitar sets through their use of different core shapes, different wrap materials and also by altering the outer wrap wire:core ratio. Lower tension sets are often more desirable for players who have older, vintage instruments especially on acoustic instruments where the bracing may be quite delicate, or for players who struggle with tendinitis or arthritis issues too where fretting heavier gauged or higher tension sets can prove problematic.
We hope this blog has been informative and helped clear up any hazy information surrounding string gauge and string tension. Sometimes these topics can be daunting, fraught with mind bending numbers and mathematical equations but they really shouldn’t have to be this way. Simply being aware of how different elements can affect the way your guitar feels and plays can be invaluable and really help you navigate the world of strings.
As always, any questions or comments simply e-mail us or leave a comment below.
We look forward to seeing you next time 🙂
To download a copy of D’Addario’s Tension Guide, simply click here