Killer Octave Question

[Ron Nossaman]

>OK then could someone give us an overview of exactly how a rib's dimension 
>and or placement effects it's performance?

Exactly, no. Roughly, yes - in a rib crowned board. Rib stiffness is 
computed with a standard beam deflection formula, like the rib was a center 
loaded beam. The rib scale is calculated from the stringing scale, with 
stiffness requirements being determined by tensions and bearing load. 
You're trying to tailer the impedance of the soundboard assembly at any 
specific point in the scale to requirements of the string scale and bearing 
at that point. Stiffness control is the more critical in the bottom half of 
the scale, and mass control more important in the top half. Positioning is 
determined by bridge type and placement, case shape, string scale, and 
whatever else you want to take into account like panel thickness, grain 
angle to the belly rail, rib to panel grain angle, cutoff bars, number of 
ribs, etc. Lots of decisions to make.


>Perhaps what possible effect either has on tone production as a whole and 
>where to look for more material on the subject?
>
>Greg

As usual, Del's journal articles, and a month's archive readings.

Ron N