[pianotech] GH-1s

[Ron Nossaman]

On 12/18/2012 10:43 AM, David Love wrote:
> Ron N:
>
> If you actually read my response you would have noted that I said
> there are times when trichords may sound better and should not be
> simply rejected out of hand.  That was all.

Odd, in response to what you actually said, I read this.
> Sure, you acknowledged it, followed by a
> general limitation of short pianos as a reason to use trichords,
> followed by the absence of permission to redesign used as a
> justification that there is a "place" for trichords under certain
> circumstances - like when you have no permission to redesign and have
> no choice, which you didn't acknowledge.

Sure, maybe trichords might actually sound better in some instances, but 
I never objected to how they sound tonally. My objections were in the 
successful matching and hammer mating of three strings, which is enough 
for me when I have the option of avoiding them.


> You've preached plenty, let's be honest.

Call it what you will, but I've always tried to support my opinions with 
as much fact as I can produce or I don't speculate.


>  When's the last time you built a
> board without or with a very modest cutoff, with modest (5.5% EMC)
> compression, more conventional and modest rib radii, with
> conventional grain angle, even modest panel thinning, with greater
> focus on optimizing the rib scale (large discussion here on what that
> means exactly) and listened to it side by side with one of your more
> recent pianos?

"Greater focus on optimizing the rib scale" is meaningless in this 
context, yes. Otherwise, the last time I did this (though a side by side 
comparison hasn't come up) was the last conventional rebuild I did 
before I started exploring redesign, and I moved away from it because I 
like the results I'm getting now much better. I think I've learned a 
couple of things since, and could do a better job now than I did then, 
but I doubt I could produce anything I like as well as what I'm doing now.


>What you are doing is
> not simply optimizing the engineering and producing a better form of
> what was there--removing the warts as you are fond of saying. It's
> changing the character of piano that didn't previously have those
> features.

Yet one of the common observations is that my pianos sound like what the 
older folks remember from when they were kids, before the Asian and 
lacquer clang became the standard.


>I'm not convinced that many people getting their design
> chops by reading the list are aware of that.

Then they need to try a few things and think for themselves, don't they?



> What I react against is the implication both
> tacit and explicit that these changes simply remove warts.  They
> don't, it goes deeper.

I've found that it doesn't matter what I say, or in what volume, nor at 
what level of detail. Someone will read and argue something entirely 
different from what I said, or focus on one small point out of context, 
or write the whole thing off because I didn't pretend that I could 
account for every nuance of tone with a hard and fast set of specs or 
numbers that could be applied without understanding of what any of it 
means. That will never change, nearly as I can tell, no matter what I 
try to do about it.


> Spring rate as such is something I look at but it's down in the list
> of several criteria that I use to determine if the rib scale is
> optimized.  By itself spring rate (deflection per designated amount
> of load for the uninitiated, e.g., mm's per lb) doesn't tell you
> much. One fundamental difference in this realm is that you use simple
> ends formulas (unless you've changed) and I use fixed ends formulas
> for beam calculations.  That tends to make my rib scales much
> lighter.   A fixed end beam (as you are aware) supports a load about
> 4 times that of a simple ends beam.

Okay. Some context. At last this is all fitting into something that 
makes sense. You're building a much more nearly conventional rib crowned 
board with a very light rib scale and moderate panel compression, loaded 
with a light bearing. This explains your preference for a light bearing. 
The board couldn't take much more, and a partially panel supported board 
(this would be a hybrid RC, rather than an RC&S board) will change more 
in tonal character as the load increases than will a RC&S board. That 
follows. Eliminating cutoff bar and fish also follows, as panel support 
allows this where a light rib scale RC&S board wouldn't support much 
load without a cutoff. This follows too. I'm not entirely sure, but I 
expect this accounts for your insistence that thinning the panel is 
necessary, as you have a minimal bearing load, you need as much panel 
flexibility as you can get just above minimal acceptable stiffness. This 
also follows, if it's correct. This is also why spring rate doesn't mean 
much to you because the rib stiffness isn't nearly as important to 
quantify with a very light load and the panel compression doing a fair 
share of the work of load support. It also somewhat accounts for your 
insistence that the ribs in a CC board are doing the same thing as a RC 
board. In a low crown light rib scale assembly, partially panel 
supported and lightly loaded, they more nearly are, where a CC board 
bears no resemblance to an RC&S assembly where the ribs are supporting 
the load.

Taken all together, I now understand much of what you're doing. Your 
preferences in bearing load, rib sizing, bass cutoff and fish, however, 
have little to nothing to do with what I'm doing, which as I've said, is 
putting a 6% or slightly above MC panel on a rib scale that will handle 
a bearing load graduated from 1/2°-3/4° in the bass, to 1-1/2° to 2° in 
the treble without any help from the panel.

Ron N