Schiedmeier Pianos and under bridge structure

[David Love]

To be honest, I don't know which one it is as I was unaware of the history
of the company.  

The only issue about whether this really contributes to stiffness is that
the underside bridge structure is tunneled out, as it were, in order to
allow the ribs to pass through the structure untouched.  While there remains
a thin piece of wood below the rib at those points, I don't imagine there is
much stiffness to the overall structure.  I don't know if I'm painting a
very clear picture.  The piano, btw, has more than adequate power.  

Maybe I'll try and stop by the piano again and snap some pictures. 

David Love
davidlovepianos at comcast.net 
www.davidlovepianos.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of John Delacour
Sent: Friday, July 06, 2007 12:49 AM
To: Pianotech List
Subject: Re: Schiedmeier Pianos and under bridge structure

At 8:29 pm -0700 5/7/07, David Love wrote:

>Tuned a Schiedmeier piano today (7'grand)

Schiedmayer?  Which Schiedmayer?  There was Schiedmayer & Soehne and 
Schiedmayer Pianofortefabrik (J & P Schiedmayer) owing to an early 
feud in the family.

>...There was a duplicate bridge structure...

Interesting. I don't think I've seen this on a Schiedmayer.

>...The piano has fabulous sustain and clarity and I'd be curious to 
>know if any other pianos or piano designers employ such a structure 
>or see the benefit of doing so.  The structure, btw, did not exist 
>underneath the bass bridge.

Yes, Grotrian used a double bridge on their grands (and maybe 
uprights) for quite a long period.  I have one on its side at the 
moment at the factory so I'll try to remember to take some pictures 
today.

>It is obviously, for mass loading, at least.

Rather for stiffness, I think.  The effect is the same from an 
engineering standpoint, and probably from a tonal standpoint, of 
having the equivalent additional height above the soundboard -- the 
tall bridge that I mentioned in a recent thread -- at 8:22 pm +0100 
11/6/07, I wrote:

>What surprises me is that so few makers have used the simplest 
>expedient to achieve a stiffer bridge, and that is to make it 
>taller, since the stiffness increases as the square of the height, 
>so that a 38mm bridge will be twice as stiff as a 27mm bridge of 
>similar construction

My first thought is that use of the sandwich bridge allows the maker 
to get the advantages of the tall bridge without needing to make 
radical changes in the design.  I'll have a closer look at the 
Grotrian soon and take measurements, but I know already that the 
bridge is also noticeably wider than normal, and no higher above the 
board than about 25 mm.

It's a while since I heard this piano, and other Grotrians, but I 
seem to remember that what it may gain in purity and sustain, and a 
certain tight-lipped "silver flute" quality in the high treble, it 
lacks in power and range.  That's not so say that this is a necessary 
concomitant of the double bridge, but it is characteristic of the 
Grotrian in my experience.

JD
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