Yow-yow-yowing bass strings

[Bill Ballard]

At 4:34 PM -0500 1/23/03, Sarah Fox wrote:
>Very cool.  Now I know the name. <smile>  Just to expand on this
>concept, if the impulse (i.e. hammer blow) delivered to the string
>has both vertical and horizontal components, and if the vertical and
>horizontal components are not simple scalar translations of each
>other (i.e. that the horizontal force is a fixed multiple of the
>vertical force, such that they could be resolved as a simple,
>unidirectional impulse at an angular direction -- highly doubtful),
>then the initial horizontal and vertical spectra would have
>different relative representations in the different harmonics
>(partials).  As a result, the resultant angle of vibration would
>differ between harmonics.  (Think about it.)  Now, considering the
>inharmonicity of the string, the phasing of the different harmonics
>would drift.  As they drift, angle of vibration at any given
>position of the string would also drift, i.e. being the sum of the
>vibrational components from each harmonic, which arguably are set at
>different angles in an imperfect system.  Add to the cocktail that
>nonlinearities in string behavior would result in the gradual
>transfer of energy from lower frequencies to their harmonics in
>the *same* vibrational direction as the lower frequencies, with
>those frequencies summating with the (slightly different frequency)
>harmonics at different vibrational angles, thus causing a shift in
>the angle of the resultant vibrational component.  YOW!!
>WOW!!  This could make a person's brain bleed!

You really enjoy "writing out loud", don't you. (Me too, along with 
bypassing the shellch-ecker <g>).

The story which I heard is from Barney Ricca, former PTG member, 
actually a physicist at one of the Texas universities. At the '95 
Albuqueque National, he was summarizing the conventional wisdom, 
saying that in the initial impact, this wave form in the string , 
viewed axially, would be purely vertical. This would last for a short 
interval (proportional to the total sustain time) until the string's 
energy would spill into the other (infinite) modes, to remain stable 
in that chaotic "omni-mode".

The initial single mode is actually the prompt sound, that time 
period when the string is feeding rapidly into the bridge. Entropy 
compels the vibrations into a choatic mode which fortunately for us, 
also extends its sustain. This latter phase is called the aftersound.

But what do I know, I've barely got a high school diploma.

Bill Ballard RPT
NH Chapter, P.T.G.

"Woh"
     ...........Keanu Reeves in "The Matrix"
+++++++++++++++++++++