<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Laminated sound boards, was Bridge design</title></head><body> <div>Greetings Del, Roger, Ron N. and all,</div> <div><br></div> <blockquote type="cite" cite> <blockquote>----- Original Message -----</blockquote> <blockquote><b>From:</b> Roger Jolly</blockquote> <blockquote><b>Sent:</b> July 09, 2002 9:46 AM</blockquote> <blockquote><br> Hi Del,<br>            <span ></span>   I think Ron Overs has done some work in this area.  The laminated board in the Overs piano is outstanding. But there is also attention to detail in every other area.<br> </blockquote> <blockquote>regards Roger</blockquote> <blockquote> </blockquote> </blockquote> <blockquote type="cite" cite><font color="#000080">Yes. He managed to make a piano using a standard, off-the-shelf Samick laminated soundboard sound very good.</font></blockquote> <div><br></div> <div>Thank you for your complimentary remarks Del, Roger and Ron N (and others, I've really appreciated your private posts). It was very encouraging for us in Reno, and the positive comments really helped to keep me going. There have been times when I have seriously doubted the merits of this crazy roller coaster ride to sleeplessness, which has consumed me for the past two years.</div> <div><br></div> <div>As usual, I get around to completing my post long after everyone's moved on to new topics.</div> <div><br></div> <div><font color="#000000">The sound board for piano 003 started out as a standard Samick board out of the piano case (although I did order deeper rib stock). It was ordered as a bare panel but it came ribbed - fortunately no bridges were fitted. I believe an important part of the tonal outcome of this instrument has to do with the preparation of the inner rim prior to installation of the sound board and the dimensions (more particularly the height) of the bridges. The inner rim was chamfered in specific areas to gain a greater radiating area in the low bass.</font> We did not use a ring bridge, since it tends to affect the low bass performance, even though it helps to control impedance problems at the lower end of the treble bridge. Instead, we used an auxiliary rib, which stopped short of the bass bridge and the inner rim on the left side, to control  the lower end of the treble bridge.</div> <div> </div> <blockquote type="cite" cite><font color="#000080">Given that, think what could be done starting from scratch and actually designing a laminated soundboard from its conception on with performance as the primary criteria.</font></blockquote> <div><br></div> <div>Indeed Del - this is happening with our next 225 piano (under construction). We are taking a bare laminated panel (yes its a Samick panel), and ribbing it with ribs which are crowned on the upper surface and flat on the bottom. We are altering slightly the board impedance at the bass/treble crossover (relative to piano 003). This will be achieved through a redesign of the rib rigidity. I am looking to move the crossover tone slightly towards the narrower end of the spectrum (but not too far), with slightly less fundamental tone at the cross. I am quite satisfied with the treble and low bass sections, but the crossover area is just a little too wide toned in piano 003 for some repertoire. We will be incorporating a substantial curved bass corner cutoff for the next piano. The cutoff will be fitted to the piano prior to the installation of the board, and will be attached to the back braces. Here again, I can't understand why manufacturers persist in fitting cutoff bars which are not connected to the back braces. It just seems to fly in the face of good design. I suspect that the idea of not attaching the cutoff to the braces allows for the cutoff to be fitted together with the sound board. But I don't care for the idea at all. If a sound board cut off is to be included (and it is better if one can afford to include one -  a real one that is, not one like the excuse we used in no. 003), I believe it must be rigidly attached to the back beams. The bass corner, at the belly, for our next piano will not have the usual sound board spruce fill. It will be filled with a veneered structural grade 19 mm ply. This will greatly improve the rigidity of the cut off system. I don't see the sense in wasting good spruce just to fill the bass corner in.</div> <div><br></div> <div>Piano 005 will be an identical piano to 004, except that it will have a solid spruce panel. I am really looking forward to hearing these two compared. I am expecting the solid panel to sound no better, but we will see.  I think they both will be a significant improvement over piano 003. We are hoping to have 004 ready for the January 03 Sydney Festival concert season.</div> <div><br></div> <div>Regards to all,</div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div>_______________________<br> <br> OVERS PIANOS - SYDNEY<br> Grand Piano Manufacturers</div> <div><br></div> <div>Web: http://overspianos.com.au</div> <div>mailto:info@overspianos.com.au</div> <div>_______________________</div> </body> </html>