String tension, scale length, tuning, simplified!

[Argh! Zombies!]

 

What we're trying to do with these strings is to get them to travel in and out, a direction at a right angle to the travel of the strings. Hence, tension only matters in that things under tension offer more resistance to travel, there are many other things that affect how hard or easy it is to move these strings.

 

 

Well doy, I know how to set up a guitar, the "dead string length" idea just threw me as relates to tension. More length beyond the nut probably just makes it easier to bend (more string to stretch) which was mistakenly perceived as less tension.

[honeyiscool]

There are several assumptions which make this calculation fail but I think the biggest one is that the assumption that the unit mass of the string is constant. Clearly this is not the case since if you stretch the string its length increases, but its total mass stays the same. However, it works well enough to give you an idea of the comparative tensions

That formula isn't intended for bending, so why are you so fixated on proving that it says something about bending?

[PrawnHeed]

 

Basically cancel out? You are increasing tension at a far faster rate than increasing string length. That first one-fret bend barely affects string length but your pitch has gone up 6%. That formula isn't intended for bending, so why are you so fixated on proving that it says something about bending?

 

 

Do the maths yourself.

 

The second point is not about bending. If you change the tuning you change the overall length of the string.

[WRGKMC]

Left out some important facts though honyiscool.

 

1. Different manufacturers use different alloys of strings and with the same gauges have varying tension.

2. The measurements are only valid for unwrapped strings. The core wire size in wrapped strings varies alot and so does the lbs pull.

3. If a guitar does not have through body string feed like on a strat or tellie, and has a stop bar or tail piece, you have to add that extra string length to the formula as well as from the nut to tuner. You need to measure from tuner to ball end and probibly the excess string you have under tension on the tuner as well.

4. You can buy short scale bass strings in all sizes and gauges, and you can cut down long scale strings and use them as well. It is true that some short scale strings are thinner strings with thinner cores, its not true there is any less tension than a long scale bass and in fact can be much higher depending on the strings you choose.

 

I've have done quite a bit of research on this over the years. (I used to measure my string tension with a spring lbs meter I got when doing specialized mechanical repairs) I can only use it on a guitar with a straight line tail piece where I can place the meter between the tailpiece and bridge. I used it to proove the validity of the Frequencator tailpice adding more tension to the low strings by making them longer and found out that its the Total string length tuned to pitch is the critical factor, not just the guitar scale length.

 

Next, i could only find two manufacturers list their lbs per string. D Addario and GHS. If you put a micrometer on the strings and guage them out, the string diameters are exactly the same yet the lbs pull on two can be different. I havent verified their lbs listing, but from what I could tell they seem to be accurate.

 

The only thing I can determine is different steel, Iron and nickel alloys have different lbs pull due to their flexability of the materials used. This is strictly the solid strings I'm talking about by the way because. The wrapped strings that are say .046 may only be a pound or two more than unwrapped strings. If those strings were solid thay would have many more lbs pull on them even though they are tuned down in pitch.

 

Wrapped strings can be all over the place in lbs tension because the core wire sizes are not standard, only the total mass that includes the wrapping which adds nothing to tension. it simply increases inertia for better bass frequencies. So you would really need to use a micrometer to measure the core wire size for a formula to work properly or to select your own strings for even tension.

 

String Diameter, total string Length, Pitch, Temp and Materials used are all key to lbs pull per string. String height is a factor as well if you're going to factor in the flexibility and feel of strings fretted. you can obviously have two strings tubned to pitch with extremely different flexibility factors. (ie steel and nylon) These are factors when you gauge strings to feel even when depressed to the frets or playing barre chords.

 

 

I think theres more to that formula than you're understanding or what D Addario is posting.

[billybilly]

That's really interesting, thanks. I play 9's on 25.5's and 10's on 24.75's. I might try a 9.5 on the shorter scale. According to the tension gauge, it should feel similar.

[Pope on a Rope]

 

In a recent thread I asked how string tree and bridge break angle adjustment could effect tension on a string in tune. Quite a few guys said it was the change in the available elasticity in the string that caused them to feel different. I have not had a chance to try the adjustment yet but your (OP) first bullet point suggest this cant be true (as does my logic). So what do they feel - if anything????????????

 

 

String tension is not affected by anything but unit weight of the string, scale length, and the frequency of the strings. Bridge, nut, or action have nothing to do with this.

 

The statement assumes that the strings are at rest. Elasticity beyond the nut or the saddles has no affect in that state, all segments of the string are at equilibrium. By changing the break angle you are changing the overall length of the string and redistributing the tension load between the outer segments while maintaining proper tension between the nut and the saddles.

 

You really should just try it yourself. Set the string tree up and down to both extremes. Tune up and play for a while at each setting.

[CoqBelliqueux]

 

What I don't like is that we're all forced into buying strings by the gauge of the thinnest string, which is spaced out at 0.001" intervals, which is such a random number, like what exactly is a thousandth of an inch to you or me or anyone? It wouldn't be overly difficult for these string manufacturers to make even tensioned string sets, and to space them out at intervals which make more sense. To have even tension across 27", 25", 25.5", 24.75", and 24" scales is impossible but it'd be nice if the rise in tension from one string set to the next wasn't such a huge number.

 

I was called a dumbass last year for suggesting that. I don't really like d'Addario, so my options are quite limited. I'll look that EXL111 anyway and find which 7th string would be best.

[MahaloVision]

There was a good article in "American Lutherie" a couple issues ago on calculating compensation. Basically the bending part is calculated figuring the core wire and the windings don't really factor in. Pretty much what WRGKMC said.

[sammyreynolds01]

Not a D'Addario fan but that is very interesting information and when you think about it makes sense.

[PrawnHeed]

This is a better discussion of the maths http://hyperphysics.phy-astr.gsu.edu/hbase/waves/string.html

[JTEES4]

I use 10's. That's the extent of my string tension knowledge. I feel so ashamed.