Guitar String Tension With Different Alloys

[StringJunky]

A question has been prompted in my mind, from another forum ( guitars) about the 'feel' (tension) of guitar strings: If two pieces of wire with the same diameter but made from different alloys (bronze and phosphor bronze) are brought to the same tension (pitch), would there be any difference (everything else being equal) in the amount of pressure required to move them laterally ie press them down on to the fret? I don't think there is because metals don't have longitudinal elasticity.....what's the fact?

[dr.syntax]

A question has been prompted in my mind, from another forum ( guitars) about the 'feel' (tension) of guitar strings: If two pieces of wire with the same diameter but made from different alloys (bronze and phosphor bronze) are brought to the same tension (pitch), would there be any difference (everything else being equal) in the amount of pressure required to move them laterally ie press them down on to the fret? I don't think there is because metals don't have longitudinal elasticity.....what's the fact?

 

REPLY:Tensile strength,flexibility would allow for a difference. I always thought metals such as copper could be drawn out in some manner. Is`nt that the way they in fact do make copper wire. I could be all wrong about this. ...Dr.Syntax

[John Cuthber]

For a given length and tension the weight of the string makes a big difference- that's why bass guitar strings are thick. They are thickened by winding wire round a string because if they were solid the stiffness of the string would make it difficult to play and also affect the frequency.

[Mr Skeptic]

As I understand it, assuming a flexible string, all you have to worry about is the tension, linear density, and length.

[StringJunky]

Thanks for your responses, but I don't think I've been very clear.....If we put two pieces of wire of equal length, say 24inches, and diameter, say 0.012", one is brass and one is plain steel, both are brought under the same tension, would they both have the same flexibility despite being made of different metal materials or would one have more 'give' than the other? Ignoring the wound strings.

[dr.syntax]

Thanks for your responses, but I don't think I've been very clear.....If we put two pieces of wire of equal length, say 24inches, and diameter, say 0.012", one is brass and one is plain steel, both are brought under the same tension, would they both have the same flexibility despite being made of different metal materials or would one have more 'give' than the other? Ignoring the wound strings.

 

REPLY: My example of copper wire would seem to answer this question. Is it called ductability,the ability to be drawn out into thin wires. Would`nt this make it flex more or not. I`m not sure at all . There`s a real chemist there if he`s still there. John, can you answer this ? The reason I used copper as an example is that it is well known for it`s ductability. It is also copper that when mixed with zinc becomes the mixture or alloy called brass. Varying the proportions varies the different properties such as hardness and ductability wich may or may not answer your question. ...Dr.Syntax

Edited October 4, 2009 by dr.syntax

[forufes]

never heard that metals don't have longitudinal elasticity..so i think there should naturally be a difference..

[DrP]

I can't give a scientific explanation, but I think that the answer is "Yes". Mainly because I play the guitar and different string sets do sound different. Phosphor/Bronze strings, for example, seem to give a "Brighter or richer" sound than plain steel.

---

Merged post follows:

Consecutive posts merged

Here: http://guitar.about.com/gi/o.htm?zi=1/XJ&zTi=1&sdn=guitar&cdn=hobbies&tm=52&f=00&su=p284.9.336.ip_p504.3.336.ip_&tt=2&bt=0&bts=0&zu=http%3A//www.stringitup.com/stringitup/strinan101.html

 

Click on the links to the different materials - they give an idea of the different sounds the strings make - doesn't explain why though. Basically it says that Phosphor-bronze are brighter sounding and silver coated are softer. Hope it is usefull - otherwise, search around a bit more.

[StringJunky]

In the above scenario with the two types of metal string under tension, I apply the same amount of force (perpendicular to the direction of the wire} in the middle of each wire, would they deviate from a straight line by the same amount or not?

[forufes]

they should! why shouldn't they? different metals, different structure, different properties, how will the atoms know it's longitudinal pull and so decide not to be elastic?

 

isn't that's all what Yung's constants are about?

[DrP]

In the above scenario with the two types of metal string under tension, I apply the same amount of force (perpendicular to the direction of the wire} in the middle of each wire, would they deviate from a straight line by the same amount or not?

 

Personally I reckon that if the tensions, thicknesses and lengths were identical then the strings would probably sound slightly different if made with different materials. When tuning a guitar though, you don't measure the tension you apply through the strings, you do it by ear and listen to the pitch and tune that in to the right note (same even if you use a machine - it tunes to pitch not string tension).

 

Thus I will stick out my neck and say that if you tuned in a steel string to top E and then a Brass one, a silvered silk one, a nylon one and a Phos/Bronze one - all into top E exactly - then the tensions in the string would be marginally different (by how much and how detectable - I don't know).

 

ALSO!!! more importantly - even though ALL of then are tuned to top E exactly - they would sound very subtley different. (same note - slightly different "shade" or "colour" - depending how you define it). For example - the phos bronze strings sound brighter and the silvered steel softer. The sound will also be effected by the attack of teh pick on the string so the material should have some subtle effect on this. This can be demonstrated more clearly by changing the material of your pick and listening to the change in the sound made by the string (same note!! different level of attack on the sound by a different material hitting the string. - my guess would be a harder, squarer wavefront for a harder material and a softer, rounder wavefront for a softer one).

 

 

I am speculating here - but pretty confident. If anyone knows for sure then please speak up.

[StringJunky]

I agree with you DrP, it's pretty much a fact that different metals sound different, bronze is brighter than phosphor bronze....My question is related to tension and how difficult or easy it is to depress the string on each type.

 

Someone on another forum was saying the two top strings (B and E) were different between manufacturers even though they were the same diameter and I had doubts.

 

There is undoubtedly a difference in the wound strings between makers because the core wire diameter to winding wire diameter varies even though the total diameter is the same between them ,hence, one will be harder to press than another.

 

Also you might be interested to know hex core strings are stiffer than round core because the winding wire grips tighter on the hex. Round wire cores last longer though because the winding wire adjacent contact surfaces remain so for longer than hex cores....once the adjacent contact surfaces of the winding wire part sufficiently, through playing, the string loses its 'chime'. Round wire strings chime more because the core wire has more movement within the winding..

'

I've played with a lot of different strings that's why one of my guitar-playing friends calls me a 'string junky'!

 

The way you've put it ,DrP, makes sense and I'm inclined to agree with you..there will be a marginal difference.

 

John's also right as well because the density of the material and hence the total mass of the string will determine the tension required to bring the string to pitch.

 

Thanks to you both for putting a clearer picture in my head.

 

Mr Skeptic: Using those three parameters and adding frequency as another. If we kept the frequency constant and wanted to change the linear density (string material), the tension would change also, yes?

 

Do you have a formula?

 

Thanks

[tomgwyther]

Two strings of different materials; under the same tension would quite obviously produce different notes. Likewise, two strings of different materials under different tensions may produce the same note.

I have a nylon string guitar and a steel string guitar. the steel guitar requires vastly more tension (About 2 tonnes) to produce the same notes as the nylon guitar.

If I were to put steel strings onto my nylon guitar and tune it up, the guitar would break in half before I finished tuning.

 

A quick wiki search brought up this.

 

The guitar strings act in such a way that they can satisfy the relationhip between wavelength and frequency, represented by the equation v = fλ . This equation can be rearranged to f = v/λ, meaning that the frequency of a wave (f) is dependent on both the velocity of the wave (v), and the length of the wave (λ). As well, the velocity of the wave traveling on the guitar string depends on the tension of the string (T) and the linear mass density of the string (µ), in fact, “the root frequency for a string is proportional to the square root of the tension, inversely proportional to its length, and inversely proportional to the square root of its linear mass density” . This means that waves will travel faster when the tension of the string is higher and in turn means that the frequency will be higher as the tension is increased (f = v/λ, the v is increasing).

[StringJunky]

Tom, Thanks for the formula.

 

How did you come to the two tonne figure? The total tension for a 25.5in scale steel string guitar with 'mediums' on is about 176ibs! I found a calculator that gives an idea of the range using different variables.:

 

http://www.mcdonaldstrings.com/stringxxiii.html