tuning effect on guitar neck

[khanh nguyen]

Hi evryone,
I have been wondering what really happens during tuning ( classical guitar) or even putting on a new set of strings . Since every time one string is cranked, the tension would result in some bowing of the neck and tilting of the bridge , pulling of the top etc.. and affect the tuning of other strings. Would having a very rigid neck help to tune the guitar more quickly and get the guitar to settle sooner? Thanks
Khanh

[Alan Carruth]

I believe that most of the issue with settling in has to do with the strings stretching: a more rigid neck would not help with that. It's hard to say whether the top or the neck moves more without some measurements. On the whole I strongly suspect that, while a really floppy neck can cause problems, an extra-rigid one probably won't help all that much relative to a normal one.

[Andrew Porter]

I've observed that tuning one string does affect the tuning of other strings. The effect is more pronounced if you are greatly changing the tuning i.e. tuning up a whole tone. By the time you've tuned the last string the first will be out of tune. If my guitar is greatly out of tune, I tune roughly on the first pass and fine tune on the second.

[Michael Lewis]

This is dealing with two different issues: nylon strings settling in, and the structure of the guitar responding to the increased tension as each string is brought up to pitch. As Alan stated, you can't get around the settling in of new strings, but a stiffer structure (body and neck) can prevent the minor flexing and consequent deformation of the guitar that causes the pitch to drop on a string as another string is brought up to pitch. Tone and volume might suffer though.

[Mario Proulx]

To answer the question, yes, a stiffer neck will help get it in tune quicker, especially if you change tunings often.

[Dave Sayers]

With nylon strings I suspect they keep stretching for ages. I'm really more used to dealing with steel strings but I think there's a couple of points that might be worth mentioning. The first is the height of the action. I generally try to set up guitar action as low as possible, and now restrict that guitar to the same make and gauge of strings for all string changes. I have found that changing makes, even at the same gauge, can cause rattles and buzzes, so different tensions are definitely moving the neck enough for it to be noticeable. I know there are some luthiers that recommend one specific string set for their guitars. The neck wood can also affect behaviour under tension. I've just finished a 12 string which was a bit of an experiment, and so I used some wood which we know as Meranti (Shorea) in England to make the neck. I believe this is known as Phillipine Mahogany sometimes. I had expected problems with the neck bending under the strain of 12 strings, but so far the Meranti has not moved at all.
In general then my conclusions would be; choose a brand and gauge of strings that you feel complete the sound of your guitar and stick to them. You will at least have an idea of how long they will take to settle in, although this can be speeded up by stretching the strings every time you pass the guitar.
A guitar that consistently refuses to stay in tune may have structural difficulties

[Tom Sommerville]

You can think of the neck as a ship's mast, where the strings act as guy wires. The truss rod in steel sting, and some nylon instruments, are designed to counter act the pull of the strings in a way that can be periodically adjusted.

So, yes, tensioning the low e string will cause the neck to deflect a little--perhaps enough to notice-- until the opposite string is brought to pitch.
Also true, a lower action will cause less bowing. A well known luthier even pointed out that fretting the string causes some deflection--enough to cause "back buzzing." (can't remember his name, maybe later)
A stiffer neck is a good thing. I've seen necks that dropped a full semi-tone when supported at the headstock while lain horizontally-with the truss rod and strings adjusted.(it was a double, bending-style rod.) It also buzzed like crazy. I think the neck resonance had something to do with the buzzing. (told customer to send it back.)