[CAUT] pre-stretching new string?

[Richard Brekne]

Actually... grin... JD's post stopped me up and I broke out my handy 
dandy spreadsheet and find he is right, and my last post in which I stated

    "As for your two different strings below... of COURSE  a similar change 
    in length will affect differently two dissimilar strings that were 
    originally tuned to the same pitch."
      

is wrong.

Take for example the two following strings. 
1:   9 mm Ø, 100 mm long speaking length, 50 mm back length, and 
192.3750 lbs
2:   8 mm Ø, 100 mm long speaking length, 50 mm back length, and 152 lbs

Both yeild starting pitch undeflected at 2070,6484 hz  and both if 
deflected 1 mm upwards at the <<bridge>> will have their pitch altered 
to 2104,7860 hz.

Thanks JD.  Spoke to fast in my last.

Cheers
RicB


        At 10:11 am -0700 10/6/07, David Love wrote:

         >Sorry, but itÕs not quite a complete enough formula for
        purposes of
         >this discussion.  When comparing two strings that produce the
        same
         >pitch but with different tensions, either the original length
        will
         >be different or the diameter will be different (or both), thus a
         >similar change in length will yield a different change in tension
         >and thus pitch.


    If this were so, then the whole basis upon which musical instruments
    are designed would crumble.  When you halve the length of a vibrating
    string, no matter how much strain is on it etc., you double the
    frequency, and if you stop two unison strings of identical length but
    of different mass, and thus tension, at the same point, you will make
    precisely the same change in their frequency and they will still
    sound in unison.  If this were not so it would be impossible to play
    a guitar in tune unless the tension of all six strings were identical.

    According to Wolfenden, if the temperature changes, and one of the
    strings is well below its yield point whereas the second is close the
    yield point, then the strings will produce a beat because the less
    strained string is more sensitive to the change in temperature.  This
    is easy enough to verify by a simple experiment, which I shall do in
    the next few weeks once the new workshop is up and running.

    JD

-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/caut.php/attachments/20070610/33e23fa6/attachment.html