Soundboard Panel Grain Angle

[Ron Nossaman]

>    There are acoustic reasons for quarter sawn wood being used.  Sound
>transmission is much better with the grain than across it, (something on the
>order of 3 times faster,too?)  I believe this is because there is a loss of
>acoustical energy every time there is a change from one medium to the next,
>and going across the grain requires the energy to go from one density of wood
>to another with every "ring line", effectively losing energy at every step.
>Harder material transmits the sound faster, too, so the harder grain
>transmits the sound better and faster than the softer "summer" wood.
>     The more truly quarter sawn it is, the more contact there will be 
> between
>the harder grain and the bridge.  There is a reason that the best sounding
>boards have the bridges directly connected to the ribs, since the ribs
>transmit the energy to the entire board with greater efficiency than if all
>the energy had to spread across the grain from the bridge. (Del, Ron??? if I
>am sinking into a quagmire here, be gentle as you yank the rescue ropes!)

Hi Ed,
I spent what seemed like half a lifetime and wrote what must have been a 
half dozen books arguing against this very stuff not that long ago. It's 
still in the archives if you want to read it, but I don't think I want to 
do it again on the list quite this soon.


>  Quarter sawn wood is
>used in the tops of fine guitars, violins, and hurdy-gurdys for acoustical
>reasons, (as well as the front and back of organ pipes).

Is it really, or are there more mundane structural reasons?

Ron N