Ron, I agree in part and demur in part. Some time ago there was a very great deal of what propeller-heads would call vaporware about bridge rolling. This product of creation's nether reaches was held responsible for everything from tuning instability to fallen arches, err, crowns. While it is quite clear that this _is_ a substantive problem in some pianos, I've certainly seen some pretty decent instruments with what would have been considered unacceptable levels of "bridge roll"...and not a few that have been severly damaged by attempts to "repair" same. Was it Susan who suggested perhaps thinnner ribs? (Sorry, braindead) In any event, several of the AA and BB M&Hs I've done over the years had not only more ribs, but smaller ones (crossectionally). These instruments came out sounding (largely) like M&H pianos used to, and had minimal amounts of surgery required to re-establish good bearing and termination. Oh, yes, most of them did not exhibit any of the tone-enhancing ridging we've heard so much about recently... Best. Horace P.S. - Come back and I will taunt you yet another time! hg At 06:21 PM 12/8/97 -0600, you wrote: >Interesting thought. Might change the frequency response on one side enough >to not cancel the other and kill the tone. > >Observation: Even if this minimized or canceled the immediate tone problems >in that area, there would still be the problem of torque with humidity >changes. I think this is what drives the board flat at this point far faster >than it flattens elsewhere. Sort of a "saddle" effect, with the killer >octave at the low point of the curve. I think both the tone problems and >early failure in this area are from the same problem. Tag! > >Ron > >At 11:11 AM 12/7/97 -0800, you wrote: >>Curiosity aroused: >> >>The "killer octave" has equal lengths of rib fore and aft of the bridge, and >>the tone has trouble there. Has anyone ever tried making the ribs the same >>length fore and aft, but making them much lighter and more flexible on one >>side than on the other? >> >>What fun ... reminds me of that great string seating thread. >> >>Susan >>----------------------------------------------------------- > > > Ron Nossaman > > > > Horace Greeley Systems Analyst/Engineer Controller's Office Stanford University email: hgreeley@leland.stanford.edu voice mail: 650.725.9062 fax: 650.725.8014
This PTG archive page provided courtesy of Moy Piano Service, LLC