# Calculating String Tension

Discussion in 'Strings [DB]' started by jneuman, May 5, 2004.

1. ### jneuman

Apr 17, 2004
South Pasadena, CA
Anybody try this?

Find the linear density of the string in question by cutting off the ends of the (old, unused) string just before the thread and weighing it on a small scale. The linear density is the weight divided by the length of the sample. You can then use the string equation to calculate the tension at a given pitch and string length. I bet this is how the manufacturers do it too, since it is easier and probably more accurate than tighting up a string with one end connected to a big scale.

2. ### Trevorus

Oct 18, 2002
Urbana, IL
well, it wouldn't be too hard to use a scale. I mean, the ball ends on strings would be easy to hook to. On a string thru body(for example), you just hook it thru the back, and tune as usual. There would obviously have to be some sort of jig to hole the guitar and the scale, but it wouldn't be tough. I am sure if you e-mailed D'Addario, they would probably tell you how they do thiers.

3. ### Trevorus

Oct 18, 2002
Urbana, IL
Woops, This is DB. This could also apply to the DB. Just having a short brige cord and scales on each string would accomplish the same thing. It would be a bear to set up, but it would not be hard. You also have to take into account the amount of gunk on a string from playing, and also the actual length of the vibrating part of the string. But that's if you want to get super technical.

4. ### Trevorus

Oct 18, 2002
Urbana, IL
here's a crappy MS Piant rawing if anyone happens to be interested...

5. ### jneuman

Apr 17, 2004
South Pasadena, CA
Yeah ,that would definitely work if I understand the drawings correctly. One could also rig up a big-A spring and calibrate by hanging some weight off of it and measuring the resultant deflection. I would be curious to know how the manufacturers measure the tension of their strings. I think there is a Thomastik rep floating around here somewhere if I'm not mistaken. Maybe he can shed some light on the subject.

One thought: Tension isn't really the whole story in terms of playability. Stiffness is a big factor in determining the easy of stopping notes. This is why Dominants feel stiffer than spirocore weich even though they are about the same tension. Maybe string makers should come up with another specification for string stiffness factor.