<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Bridge design</title></head><body> <div>Hi all,</div> <div><br></div> <div>Dale wrote;</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" color="#000040">. . . Oddly enough I just purchased 2 Mason As . One from 1929 and the other 1931. The 1929 has the usual long tenor bridge and the other has a modified tenor bridge. The bridge makes an abrupt swing towards the staight /bass side of the case. This shortens up the speaking length bout 3 or 4 inches and on it are of course 5 wrapped bi-chord unisons. The plate area at the agraffes is also shortened appox. an inch.</font></blockquote> <blockquote type="cite" cite><font face="Arial" color="#000040">  I found this to have a very good bass tenor break and a step in the right direction with this model considering the break with plain wire has been changed i different wire size configurations over time. And with not much success. To bad that Mason& Hamlin didn't stick with it. No doubt more costly .SO WHAT. Any rebuilder could easily duplicate this modification except the agraffe change.</font></blockquote> <div><br></div> <div>While it is possible, for pianos which have bichords on the long bridge without employing a transition, to achieve a good tonal transition from the tenor to the bass bridge, the transition from plain trichords to covered bichords will always be a mess. There is just no way of scaling a way around the problem without having a reduction in speaking length in the adjacent bichord note (this can be proven with both the tuning lever and the spread sheet).</div> <div><font face="Verdana" color="#000000"><br></font></div> <div><font face="Verdana" color="#000000"><i>Del wrote;</i></font></div> <div><font face="Verdana" color="#000000"><i><br></i></font></div> <blockquote type="cite" cite><font face="Verdana" color="#000080"><i>A better solution would be to straighten out the scaling in that area and use an extension on the end of the tenor bridge to stiffen up the end of the bridge</i></font></blockquote> <div><br></div> <div>Indeed Del, we use an extension at the end of the long bridge to achieve the impedance we're after. A ring bridge might well stiffen the low end of the treble bridge, but it will also stiffen the low end of the bass bridge, which is not exactly what we want at A#1.</div> <div><br></div> <blockquote type="cite" cite><font face="Verdana" color="#000080"><i> -- even better, design in a transition bridge -- and/or redesign the ribbing, and leave out the gaps.</i></font></blockquote> <div><br></div> <div>Agreed. Of course, the transition bridge is a really sensible work around for a piano which has bass/treble break which is lower than desirable, for the particular length of piano.</div> <div><br></div> <div>Interestingly, something I have noticed about transition bridges is that they also need an extension running out from their treble end, to increase the impedance. This extension would therefore run further out towards the center of the board. I am thinking now that it should be long enough to run over another sound board rib. Of course, none of this stuff would be necessary if the cross was in the appropriate place to start with. After a hundred years we are still stuck with a multitude of small and mid sized grands with the cross scaled too far down, just to make them look like their bigger brethren.</div> <div>Its time the marketing department was gotten out of the scaling room, 'cause all we end of with are little grands which are pretty, but pretty damn useless.</div> <div><br></div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div>_______________________<br> <br> OVERS PIANOS - SYDNEY<br> Grand Piano Manufacturers<br> <br> Web: http://overspianos.com.au<br> mailto:info@overspianos.com.au<br> _______________________</div> </body> </html>