Soundboard Thoughts

[Ron Nossaman]

Hi Newton,

Right, as usual, by gosh. I went out and looked again. The treble has more
rib length behind the bridge, the tenor and bass has more in front. Guess
where the transition point is where the rib length is equal on both sides.
%-) Yep, smack in the "killer octave" problem area. This makes a lot more
sense than my original thoughts.

With a couple more brain cells activated, I checked out the monster tone bar
idea again. It looks like a roughly similar ratio of rib length fore and aft
of the bridge can me maintained through the whole scale at a cost of between
fifteen and twenty percent of the total soundboard area. Seems like a big
chunk, but the tone bars I see installed in that area in existing
instruments already indicate that the front bass corner doesn't have much to
give toward tone production anyway, so maybe the hoped for improvements in
sound production would outweigh the loss of area. Since that extra area in
the bass is fighting the board movement in the treble, I'd expect the net
effect of the change would be positive. We would still get the proportional
narrowing of the board (sort of) corresponding to the frequency of the sound
produced at that point on the bridge, so the rest of my original scenario
still seems logical. This modification would also reduce the torsion on the
bridge with humidity changes and probably maintain a crown in the high
tenor/low treble better than the current configuration. I like it. It's
simple, logical, and pretty, at least until someone shoots it down with
another "faulty premise" correction. %-) It's a better fit now, I think,
thanks for setting me straight.  

Ron

At 10:01 AM 12/1/97 -0500, you wrote:
>Dear Ron,
>
>If you watch drummers you will notice that they play along the side of
>the head, not the center.  If a rib cuts a soundboard in half, you will
>loose tone and power because of the cancelling effect of the equally
>split bridge.
>
>Some of your other thoughts sound good.  Perhaps DDF will jump in since
>he seems to know more about soundboards than anyone else I know.
>
>Have a nice week.
>
>	Newton
>	nhunt@jagat.com
>


 Ron Nossaman