Check out what Ron Overs does to the soundboards for grands he re-manufactures from Asia... http://overspianos.com.au/OS003.html Also, a few years ago Schimmel did research, and came up with their "Schimmel resonance system" Diaphragmatic cross section of soundboard** Soundboard tri-dimensionally crowned Strong ribs for excellent energy distribution One sound reflection bar See if you can find more info on this process.... This would be hard to "retro" into a pre-existing Zimmerman, but I'll bet you could use violin planes to do this. (Check out the violin planing methods, i.e. tapping, and transducer tones) Are you proposing to remove the strings/plate, and work on the board in the piano? How will you modify the ribs to make them stiffer,if that's the problem? Is the back open enough to get them in there? What about the added weight and mass? Perhaps you could "cap" them ala Overs. (See his website for those I-beam ribs). Well, I had one customer with this tiny (tinney) Zimmerman grand, and the sustain was very short, and very shallow bass, many, many false beats, etc. It's my only experience w/Zimmerman. (4'10") I wouldn't expect it to have much bass, and it doesn't. I think you need to take many soundboard and rib thickness measurments over the board and see just what kind of board set up you have there. Maybe Ron Overs or one of the other piano designers could help you out. I would wonder if it is worth your time financially, as you'd not get much out of these in resale. good luck Ric, RA -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/20071210/cf327cf0/attachment.html
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