Killer Octave & Pitch Raise

[Ron Nossaman]

>My question is - might these two phenomena be related? Is the killer 
>octave area more prone to going flat because the bridge is rotating (I 
>suppose in part due to soundboard not having enough support in that area)?
>
>Thanks for any thoughts.
>
>Terry Farrell

I think so. The tenor isn't heavily loaded, and the soundboard (usually) 
supports it, though it sinks some. The upper treble section is heavily 
loaded, and barely sinks at all because the bridge is very close to the 
belly at the top end. It's sitting on a brick, essentially. With the top 
end of the bridge as a fulcrum, any load put on the treble levers down to 
the curve in the bridge, where it loses beam support because of the curve. 
So the killer octave has to support not only it's own heavy bearing load, 
but gets additional load from both the tenor and treble by virtue of being 
at the end of two third class levers courtesy of that curve. 
The  soundboard deflects proportionally more at the curve, and the bridge 
rotates with it's center of rotation being a line through somewhere at the 
top end, and somewhere in the mid tenor. The part of the bridge furthest 
away from this center of rotation is the curve, where the killer octave is. 
This is also why it's possible to have both negative crown and negative 
overall bearing in the killer octave.

Ron N