Steingraeber factory pictures, bridge agraffes & adjustable vertical hitchpins

[Overs Pianos]

Calin, thanks for posting the images to your  web space. They were interesting.

>At 10:48 PM -0500 2/5/06, Ron Nossaman wrote:
>>Yes, the string bearing is reversed, but the concept behind is that 
>>you don't have tension sideways on the bridge, which helps the 
>>soundboard vibrate more freely.
>>
>>Yoshi
>
>And how does that work? In my world, the soundboard isn't changed by 
>the string termination at the bridge, and will vibrate pretty much 
>the same with either system. The real difference is in the mass on 
>the bridge which, if anything, will impede the vibrational freedom 
>(amplitude, in this case) of the soundboard assembly by lowering 
>it's resonant frequency, increasing it's mechanical impedance, and 
>extending sustain.
>Ron N

Agreed Ron N. Stuart also makes the claim that the horizontal forces 
of the string offset affect the vibrational freedom of the 
soundboard. I don't believe it.

>. . .  a lot of speculation . . . I did put the question directly to 
>Wayne Stuart about a year ago . . . he [claimed] the concept was 
>well researched and documented mathematically by CSIRO Mathematician 
>Dr Bob Anderssen  who did the research and that anyone who wanted to 
>could contact him if they wanted more infomation.  To quote:
>
>Dr Anderssen has found out how the new coupling method is 
>responsible for the wonderful clarity of sound that the Stuart 
>pianos produce. By exploiting existing knowledge about piano sounds 
>and string vibration, some of it over two thousand years old, Dr 
>Anderssen was able to build a mathematical model of the way piano 
>strings vibrate. "The model reveals how, in standard grand pianos, 
>the strings begin vibrating vertically but change to vibrate 
>horizontally, parallel to the soundboard," Dr Anderssen says.
>
>"This change to a horizontal vibration makes the sound less 
>harmonious." "But, in the Stuart piano, the vibrations stay in the 
>vertical plane because of the special coupling method implemented by 
>Stuart. This gives a more harmonious and stronger sound," he said.
>
>Strikes me that if folks want answers to these questions then 
>Andersen is a good place to start... followed up by a good deal 
>controlled testing.  Speculation... armchair or otherwise may be fun 
>and perhaps even thought provoking... but it remains speculation.
>
>Cheers
>RicB

Strikes me as smoke and mirrors. Notice that Anderssen built " a 
mathematical model". Did he build a real-world model on the bench? 
While Anderssen has made certain claims, there is nothing offered by 
either Stuart or Anderssen in the way of oscilligrams or other such 
results to support their claim. If they had any hard evidence it 
would surely have found its way into either brochures or the Stuart 
website. But there's nothing, just the claim.

Some time ago, when a Stuart piano was at a Sydney venue that we 
service, I did some of my own 'research' with a sophisticated tool 
called a trouble lamp. I placed the lamp in close proximity to some 
strings on the Stuart piano and played the note to watch the 
vibrational mode during the string's decay. As expected, when 
initially struck the string vibrated in a vertical mode and as the 
tone changed from the initial high-level to the lower-level long 
decay, the mode of vibration changed to a circular mode just as it 
does on every other piano on the planet. Just think about it. In a 
regular piano the offset at the bridge is horizontal while the offset 
at the capo is vertical. Making the bridge offset vertical won't 
miraculously result in a persistent vertical vibrational mode. In any 
event, if it did you would end up with less sustain not more.

I'm not suggesting for a moment that the bridge agraffe isn't 
beneficial to tone. I certainly suspect that it is, but not in the 
way that Anderssen and Stuart claim.

At the launch of the first Stuart pianos in Newcastle, Goeff Pollard 
and I spoke with Robert Anderssen, and when asked about the research 
which was undertaken, he said that exhaustive tests hadn't been 
carried out.

[re the Dain agraffe]
Was interested to read that the agraffe on the Stiengraeber grand was 
a Dain invention. It is a very good design, and superior to the 
Stuart agraffe, which results in string noise without the silicon 
blocks that he uses. Mr Dain has beaten me to the public domain with 
this one.

Ron O.
-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
_______________________

Web http://overspianos.com.au
mailto:ron at overspianos.com.au
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