rim laminations

[John Delacour]

At 21:55 02/10/01 -0700, Delwin D Fandrich wrote:

>...Acoustical stiffness. I've not done any testing at all, but I don't see the
>traditional rim, i.e., all longitudinal laminates with no crossbanding,
>providing any better acoustical stiffness to the soundboard than one with
>crossbanding. In fact, assuming the wood used is the same in both, I could
>provide a reasonable sounding argument in favor of the crossbanded rim. At
>least I've talked myself into it.....

Yes, me too, at least for a prototype that I'm building at the moment whose 
primary function is to test the possibilities of a new type of soundboard.

The fact is that it's very easy to build a rim the way I'm building this 
one, with very flexible lengths of 3-ply birch.  It has always been my 
intention to use such a rim simply to prove the concept of the board and to 
switch to mainly horizontal laminations of maple, beech and/or ash further 
down the road.

Birch ply is dirt cheap and can be got in good qualities (imported from 
Finland) at any timber merchant here.  I'm not too fond of birch in pianos, 
but mainly because I've seen it turned to dust in so many uprights by the 
beetles.  This is not really sufficient reason to exclude it as rim wood, 
since it can easily be protected -- and besides, the beetles are not averse 
to a good bit of maple either -- so I want better reasons for hating 
birch.  Can you give me those reasons?

JD