This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Dale, This is true only if the soundboard assembly is compression-crowned where the thickness of the board is necessary to support crown over the years. It's why diaphragmed soundboards collapse more rapidly than do thicker boards. If the soundboard is crowned using curved ribs the bulk of the crown support comes from the rib and the panel functions more as a non-structural diaphragm. In this system the thickness of the soundboard is chosen based more on acoustical needs and less on structural requirements and 8 mm is quite adequate. This is especially true if a reasonable cutoff bar and a fish are used. Del _____ From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Erwinspiano@aol.com Sent: June 20, 2005 10:32 PM To: pianotech@ptg.org Subject: Re: Rib Crowned Hamburgs ? Ron 8 mm /.320ish is on the thin side for a 9ft grand of any make . A board this thin doesn't really need much thinning. In fact it's probably not thick enough in the treble. I'm unaware of the German factory's rhetoric on panel thinning. I'm guessing it sounded a bit thin? grin Regards Dale Very often the factory line doesn't match the actual product. How often have we heard about the tapering of sound board panels from S&S. They may have done it at some time but . . . The original board which I pulled from a 1962 Hamburg D last year had a 8 mm thick panel everywhere. I still have the original panel at the workshop. Ron O. Erwins Pianos Restorations 4721 Parker Rd. Modesto, Ca 95357 209-577-8397 Rebuilt Steinway , Mason &Hamlin Sales www.Erwinspiano.com ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/5b/b0/e8/18/attachment.htm ---------------------- multipart/alternative attachment--
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