String tension

DeeTee

This is something I've been confused about for a while. I see lots of people saying that the string tension on one guitar is different to another, when they're the same scale length. I would have thought that if the scale length and string gauge is the same, the tension would have to be the same or the pitch would change?

The only thing I can think is that they saying it's easier to bend the strings, because there's more string behind the nut or bridge to compensate. I'm sure I'm overlooking something obvious, would be grateful if someone could explain.

Funkfingers

Even with equal gauges and scale length, the ACTUAL tension will vary with things such as a vibrato system.

SteveRobinson

For any given set of strings, scale length and tuning, the actual tension is always the same.

The *perceived* tension can be different depending on the setup, the type or absence of tremolo system etc..

DeeTee

So it's as I thought - string tension will actually be exactly the same. There's just a perceived difference, probably due to the amount of string available to pull on beyond the contact points of nut and saddles?

mart

SteveRobinson said:

For any given set of strings, scale length and tuning, the actual tension is always the same.
..

This is correct, but note that strings of the same gauge may give different tension for the same scale length. 

The tension is dependent on the mass of the strings, whereas the gauge is effectively a measure of volume. So strings made of different materials, with different density, can have the same gauge but give different tensions.

SteveRobinson

I think setup makes a huge difference. A straight neck requires a lot less finger pressure than one with significant relief.

more

There is  some  small variation in the tension of wound strings, but the basic equation is simple. The mass of the strings , gauges, and the scale length of the guitar will determine the tension. Longer  scale length  the higher the tension. So two Guitars with the same gauge strings and the same scale length will have the same tension. But that is not to say the playability and feel will be the same .  A poorly  set up guitar will be harder to play than a properly set up one, even if the guitars are the same make .       

Roland

Scale length, gauge, and the diameter of the core wire, are the principal determinants of tension. As a lot of people have said, ease of bending is affected but set up. It’s also affected by string length, ie how much there is outside of the saddles and the nut.

Alterlifeson

I find radius and fret size to be significant contributors as well, particularly when bending. The curvier radius means you are pushing 'uphill'. Smaller frets mean your fingers are more likely to drag across the fretboard creating more resistance.

But yes, in principle it is the perceived differences rather than actual differences in tension.

Slash'N'burn

Break angle over the nut or bridge can make a guitar feel different.

 Raising the tailpiece on a Les Paul just a bit makes for easier bending.