Stretch tuning a resistor string... why NOT to!

[Don Tillman]

   Date: Mon, 17 Jan 2000 00:56:25 -0500
   From: KA4HJH <ka4hjh at gte.net>

   As I understand it, in the real world elastic materials become more 
   resistant to being deformed the more rapidly you try to deform them, 
   and so the deformation gets propagated more rapidly. 

Nah...

Guitar players are intimately familiar with this effect.  The issue is
that the ends of the string are a little stiffer than the middle of
the string because the ends are mechanically connected to larger
pieces of metal such as the bridge, nut or fret.

Harmonics and fretted notes played higher up on the neck have shorter
wavelengths, and the stiffer region of the string near the ends is
proportionally greater for these shorter wavelengths, so higher
harmonics and fretted notes higher up the neck are progressively
sharpened from what you'd expect.

Guitars compensate for the sharpening of higher-fretted notes by
moving the bridge sections a little bit farther back than they would
be placed theoretically.  More so for the larger-diameter bass strings
as they have more contact with the bridge.  You'll see this more in
electric guitars than acoustic guitars, and even more in electric
basses.

Adjusting the bridge sections so the higher-fretted notes are in tune
is called "adjusting the compensation" in guitar-speak and is part of
the setup of the instrument.

  -- Don














This is what makes the pitch of the overtones increasingly 
   sharp (they ain't harmonics anymore). This is also one of the reasons 
   why the DX7 (the first affordable FM synth) was so incredibly 
   popular--FM can simulate this.


   BTW, this is also the main reason why I absolutely hate synthetic 
   percussive metallic timbres. Every cheesy ballad on the radio has one 
   in the mix somewhere--along with the explosive, gated-reverb snare. 
   Thank god someday we'll be out of the eighties.

   Terry Bowman, KA4HJH
   "The Mac Doctor"

   ICQ: 45652354