Upright and Grand rims, was: Impressive Steinway Upright

[gordon stelter]

Dear Terry,
     Well, I try to avoid "magic circles" ( remember,
I'm still a monk ) but would imagine that a curved,
laminated rim would do better at passing the
vibrations around the board's perimeter to where they
could be most easily re-transmitted into it ( as well
as reflected, by the curved rim's ability to withstand
stress from the outward pressure of the
board--remember the arch principle.  But it would also
provide a superior reflection point if it follows the
perimeter of the board's most lively portion. On an
upright, as has been so nicely pointed out, there's
not much sense in reflecting vibrations back to the
corners ( hence the cutoff bars ).  And I imagine that
vibrations would prefer travelling around a
continuous, bent rim, rather than negotiating
right-angles and glue joints. 
     Respectfully,
     Gordon Stelter
--- Farrell <mfarrel2@tampabay.rr.com> wrote:
> > Bush and Lane(and a few others)
> > made uprights with an actual curved, laminated
> "inner
> > rim" which I believe acted as "cutoff bar" as well
> as
> > sending the vibrations around the board and
> reflecting
> > them back into it, like a grand rim would.
> 
> This is what I am describing on the S&S upright. And
> are you speaking in reference to the "magic circle
> of sound"? Does a laminated rim "reflect" sound
> better than a solid timber frame?
> 
> Terry Farrell
>   
> ----- Original Message ----- 
> From: "gordon stelter" <lclgcnp@yahoo.com>
> To: "Pianotech" <pianotech@ptg.org>
> Sent: Sunday, September 15, 2002 1:02 PM
> Subject: Re: Upright and Grand rims, was: Impressive
> Steinway Upright
> 
> 
> > So are these "rubbish sounds" just specific,
> > sympathetic resonances picked up by the spruce in
> > areas where he daming of the strings would not
> supress
> > them ( corners?)? That's what I have always
> thought
> > the "cutoff bars" were for: to dampen soundboard
> areas
> > prone to this effect. Bush and Lane(and a few
> others)
> > made uprights with an actual curved, laminated
> "inner
> > rim" which I believe acted as "cutoff bar" as well
> as
> > sending the vibrations around the board and
> reflecting
> > them back into it, like a grand rim would.
> >      Gordon Stelter
> > 
> SNIP
> 
> _______________________________________________
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