[CAUT] tone color

[David Love]

And my guess is that the added stiffness in that whole assembly is what
drove him to have to use a very massive and fairly dense hammer on that
piano such that it needed wippen assist springs (and an 18 mm knuckle
hanging--or was it longer, I don't recall exactly now) to function within
normal range, though I'm talking about the piano I saw in Reno and not in
Rochester--I didn't go to Rochester.  That formula changes the tonal
signature a lot when compared with the RC&S boards that I'm used to where
they are easily driven by an unadulterated Bacon felt hammer.  Those are
important differences in terms of what the piano will produce with respect
to partial development at different levels and the damping effect of a soft
hammer when played hard (an important issue in this discussion).  I don't
think you can separate the hammer from the belly in this respect.  

David Love
www.davidlovepianos.com


-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Ron
Nossaman
Sent: Thursday, February 24, 2011 7:45 AM
To: caut at ptg.org
Subject: Re: [CAUT] tone color

On 2/23/2011 10:49 PM, David Love wrote:

>The belly of the Overs piano was very different in its weighting and hammer
> requirements.  While they both employ some similar features, I don't think
> you can really compare the two in terms of panel characteristics or rib
> scales.

Ron O's pianos are more heavily ribbed than most, so the assembly will 
be stiffer. But the other component has been almost universally 
uncommented on. The panel adds considerably more stiffness to the rib 
support than most realize. Being a laminated panel is what makes this 
work so well. There is vastly less cross grain compressibility in this 
panel than there would be in a solid one.

I built a demonstration model years ago. A roughly 800mmx200mm piece of 
old 5mm Yamaha crate plywood, sprung in a curve and a (one, in the 
center) straight 25mm wide x 20mm deep straight pine "rib" sprung into 
the curve and glued in. Both components are trying to straighten back 
out, but glued together, they can't. If the panel was cross grain solid 
spruce, there would be some obvious spring to the assembly as you pushed 
on it. With the more nearly incompressible plywood panel, the assembly 
is amazingly stiff. I have something like an 8mm crown in this thing, 
and a handy 215lb mass load that I happened to have around won't force 
it flat. Ron's rib scale on a solid spruce board wouldn't work anywhere 
nearly the same.

Ron N