The flexibility of the guitar's top and neck can affect string tension??

[Mark]

Hi all, I was reading about string tension on the daddario web site.

http://www.daddario.com/DAstringtensionguide.Page

It says 'The flexibility of the instruments top and neck can affect string tension'

I'd like to know how so??

Any thoughts?

Cheers.

[Roger Häggström]

They say; "There are many factors other than string gauge that determine the actual and PERCEIVED string tension on your instrument".  The flexibility of the instruments top and neck and neck relief don't affect the tension, only the perceived  tension.

[LARRY KLOSE]

Weather and temperature can both affect tension--the tuning will change, i.e. a change in tension, with more or less humidity and/or heat unless the top is very, very stiff--like a laminated top.  A high quality, well built instrument with thin top plates and light bracing will move (tuning drops or rises) more with humidity and will even change with body heat.  I have a couple of instruments that always need re-tuning after I hold them close for a while--they absorb body heat.  The tension change may not be much but it's there.

Larry

[Mark]

Larry, so are you refering to the top swelling and rising because of temperature & humidity changes? Therfore raising the action and creating more 'tension'?
Or can the top and neck actually move in a stretching and pulling way creating more tension on the strings?
Thanks.

[Dave Domizi]

Hi Mark,

If the guitar is properly tuned at each time of playing, then as Roger said, the only question might be “perceived tension”. Essentially, what this refers to is the amount of “give”, or flexibility, of the guitar’s wood in reaction to the minor difference in tension created by pushng the strings down onto the frets when playing (makes the string tighter). Once tuned for play, I doubt that most people would encounter much perceptible sag in tension due to wood flexion, but if so, it would also likely cause intonation problems, and would really fall into the category of construction defect, ie - under engineered stiffness of the top and bracing, and/or neck.

Cheers,

Dave

[Dave Domizi]

Of course, if the action is higher at pitch due to a climate change, then the higher action will increase the tension of a fretted note (longer distance to stretch the string to the fret), but it doesn’t change the tension of the open strings.

[Russell Vance]

HI All,

The string tension in the tuned or quiescent state is what ever the tuning is.  I assume that D'addario intended this statement to mean that once the guitar is being played that the string tension and subsequent feel and response will not be the same for all instruments.   

Any deviation from this balanced state by way of applying a guitarist to the equation will generally result in an increase in tension of the strings.  The degree of this increase affecting the feel of the stings under playing conditions will be related to the flexibility of the soundboard (and some other things not related to answering this question)..   Its not a linear equation because  their is "give" in wood under stress and there are changing angles and leverages involved as the soundboard deviates from its normal orientation.   

A few other variables affect this and no doubt they will be teased out in subsequent posts - which is valuable because it helps understand (and helps me understand)  that vexing problem of why some instruments feel so good to play while others seem to fight against you.    

Good subject, good questions,

Rusty

[Mark]

Thanks everyone for your useful comments.

Like Rusell pointed out. I too am trying to understand  why you can have two identical guitars with the same specs such as

the same string break-angle or length at the nut and saddle/bridge, length of the string between the tuning posts,gauge of strings,action height etc etc, and one guitar can feel great and the other 'stiff'.

I understand it's also such a subjective thing.

What may feel stiff to one player may feel great to the other.

Cheers!