There is some good information on this topic in McMorrow's book: "The Educated Piano", page 83 under the subheading: Detuning the Duplex. At 08:39 AM 9/26/97 -0700, you wrote: >Hi Lance: > >The main problem with the model L is that there is an unhappy length >combination between the speaking length and the counter bearing length. >That's why putting some glue on the aliquot length helps; it changes >the frequency of that segment so that is does not resonate with the >speaking length of the string. Caution do not let glue run down to the >Capo Bar. As a result of my studies of this, the SF10 first came out >with individual termination peices that were of different lengths. This >was also applied to the SD10. Why something was not done to the L is >hard to understand since it was one of the worst offenders. This problem >is worse on the several notes just above where the Capo Bar begins. > >Jim Coleman, Sr. > >On Thu, 25 Sep 1997, Lance Lafargue wrote: > >> I asked about this a few months back. I'm surprised that Baldwin has not >> issued some statement of recommendation on this matter. 90% of the >> Baldwins I see from the 70's and early 80's have this problem. One of my >> customers paid $800 to send her R back to the factory to correct the >> problem and it was exactly the same. They restrung it, but left the old >> string marks on the capo bar,etc. >> >> I got temporary results by filing the bar, but it came back. I have >> reduced some of it with a drop of glue or felt mute between the bar and the >> plate ridge near the pins. I suspect downbearing, but that's mostly >> because it's the only thing I haven't tried. It is so loud and annoying >> that it renders the instrument useless on a few of my customer's pianos. >> I've got SD-10s with it too. I find the problem in Young Changs a lot >> also. >> >> It must be predominantly ONE common factor. But what??? >> >> Lance Lafargue, RPT >> New Orleans Chapter >> Covington, LA. >> lafargue@iamerica.net >> >> ---------- >> > From: Rob Kiddell <atonal@planet.eon.net> >> > To: pianotech@ptg.org >> > Subject: Capo bar noise >> > Date: Sunday, September 21, 1997 2:56 AM >> > >> > Greetings list, >> > >> > I'm currently working on prepping a new Baldwin L grand (6'3"), and >> > there is a problem with excessive high partial noise from the first >> > section of strings above the agraffe section. Simply put, it is an >> > excessive high partial ringing that is absent in the agraffe section, >> > but becomes immediately apparent in the Capo bar section. This noise >> > is so harsh as to qualify for ear protectors on a ff blow. It is >> > amplified by the front duplex section between the Capo bar and the >> > first plate ridge past the tuning pins, but muting this kills all >> > high end frequency and leaves the section lifeless. Hammers are hard, >> > but voicing (I've tried several approaches) only diminishes the >> > overall hammer volume, the amount of the high end noise remains >> > consistent with the overall volume of the note, either mellow, medium >> > or bright. This noise is also evident when the string is plucked, so >> > I feel hammer voicing is not the solution. I have seen this problem >> > before on Baldwins, but strangely enough, the identical 6'3" piano on >> > the sales floor exhibits none of this "noise", yet the front >> > duplexing section on this piano is amplifying high partials as it >> > should. >> > I have spaced strings along the capo bar, streched >> > strings, seated strings, muted strings, yet everything seems to come >> > back to the Capo bar. Before I begin filing the Capo bar, are there >> > any thoughts out there regarding this or similar problems? >> > >> > >> > Rob Kiddell >> > R.P.T., P.T.G. >> > C.A.P.T. Student >> > Edmonton, Canada >> > http://www.planet.eon.net/~atonal/atonal.html >> > > Rob Edwardsen 21 Courtenay Circle Pittsford, NY 14534-2101 716-586-1360 edwardsn@rpa.net
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