String Height vs. String Tension

[SDK_CFA]

I have a couple of questions for those who know more than I about guitar construction (probably anyone who reads this post!). I just re-strung my Alhambra 11C with high-tension strings, and it appears the string height is now higher than it was before I made the switch.

First, am I imagining the change in height? And second, is using high-tension strings riskier than normal tension strings for any reason?

Actually, I'm kind of worried!

[Jonny Hotnuts]

Very likely the high tension strings (I use them also) are pulling the neck forward.
If you dont have an adjustable truss rod I would say you are s.o.l.
If you do have an adjustable truss, crank it down a bit and it should take care of your issue.
Only thing I would really see as a problem is if the top was bowing up (very bad but very unlikey) or the neck joint was comprimised.

But I really dont have a clue what I am talking about so dont listen to me.

-JH

[M. Stephenson]

Higher tension strings can bow a neck. Guitars are made to use certain tension strings - you might want to check the Alhambra website or talk with a Alhambra dealer about the recomended string brand and tension.

Look down the neck from the tuning machines and see how it looks. There should be a light even bow. If the bow seems to have more change at the joint between neck and body, I would recommend removing the high tension strings sooner than later.

If it appears that the string tension is causing the bow and the strings have not been on for an extended period of time, then changing back to a normal tension string should allow the neck to re-settle into its original bow.

If in doubt, visit a luthier. He/she will be able to make an accurate assement and will advise on the proper course of action. It may be that some adjustments cam be made to the nut and/or saddle to allow you to continue using high tension strings.

[keith]

you may want to do actual measurements with high tension and medium tension strings on the guitar--measure the height at the 12th and 6th frets. what you may be experiencing is not actual changes in height, rather, a greater force needed to fret the string.

one thing you may want to check out: one company's high tension is another's medium.

[Jonny Hotnuts]

I worked for a large guitar manufacture for about 4 years when I was in school, doing many jobs and ending up as team leader for guitar R&D. And while they were solids this is how we told our techs how to set up bow.

1: depress low E on first fret and hold (left hand)
2: with thumb of right hand fret the highest fret on the E at the same time and hold.
3: with both held, correct bow can be mesured by the distance of the string to the fret at the 12th. (There should be a small air gap under the string at the 12th you can use your "I" finger on you right hand to reach over and press down till it hits the fret.)

I can not remember what the mesurement was but was but visually you should have between 1/2 to the entire thickness of the E string. Somewhere in the range of a 32nd to 16th of an inch.

Looking at my cervantes and taylor it seems to be the case with classicals as well.

[keith]

to add to jonny's post, and the previous post concerning the strings pulling on the neck--these figures are from an earlier post.

here are the heights for classical and flamenco guitars as used by jose ramirez and jose oribe---from their published books.
again, measure with the hard tension and then the medium tension. if there is a difference in measurements, the hard tension pulling theory may be correct. do factor in the guage of the string (which should be minimal).


classical at 12th fret low e 4-4.5mm high e 3mm
flamenco at 12th fret low e 3-3.5mm high e 2-2.3 mm

now to the nut: adjustment to the action should always be done at the saddle. but nuts do wear, etc. jose oribe uses a feeler guage (purchased at auto supply store). he pushes down at the third fret and uses the feeler guage at the first fret (between the top of the fret and the bottom of the string). these are his actual figures (in INCHES)

1st string .002-.005
2nd string .003-.006
3rd string .008-.012
4th string .003-.006
5th string .005-.009
6th string .008-.012

when you use a feeler guage, it should slide with a little resistance--no resistance means the space is greater than the feeler guage used, a lot of resistance, the space is less. i would start by using the higher end figures and move south, so to speak, as needed--e.g., for the first string, .005. hope this helps.

[SDK_CFA]

Wow! You guys are great! Thanks for the help.