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 -- ______________________________________________________________________ Delacour Pianos * 34 Station Road * Poole * Dorset * BH14 8UD Phone: 01202 731031 * Mobile: 07801 310 689 * Fax: 0870 705 3241 ______________________________________________________________________
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