Compression Question

[Bill Ballard]

At 9:51 AM -0700 8/29/03, Delwin D Fandrich wrote:
>I would assume that only if I knew the manufacturer in question was
>primarily compression-crowning their soundboards.

I should know better by now than to assume what you would assume......

Stop me if you've heard this one before, but...
is there any reason why low EMC board ribbing and compression 
crowning necessarily go together, or is it an accident of history?

I also gather that it's the low EMC panel assembly which causes most 
of the damage. For each assembly EMC, the ceiling EMC (and by 
correlation ceiling ambient RH) beyond which compression damage 
occurs, is set. The lower the assembly EMC, the lower the maximum 
ambient RH it can withstand before damage occurs. The lower the 
maximum ambient RH, the less headroom the owner has in controlling 
the piano's environment

Again, stop me if you've heard this one before (or send me to the 
archives), but in a panel with significant compression ridging but 
thus far without the consequent cracking or break-down of rib-board 
glue joints, what is the effect on board resonance, you know, the 
magic tone disks? Or will the damage to resonance only show up as a 
result of board-rib separation, prematurely brought on by the 
compression damage?

TIA,

Bill Ballard RPT
NH Chapter, P.T.G.

"What's this kid good at?
"Oh, lying.
Great, we'll send her into public relations"
     ...........AM radio psychologist Dr. Joy Browne and the 
exasperated mother of a teenager.
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