I'm with Barbara, in that I don't want to make a big change to the bass when it is often in the ballpark and the problem is tenor/treble. 2 quick times through the problem area and you have made a big improvement. Sounds like a damp-chaser would solve this problem... David Ilvedson, RPT Pacifica, CA 94044 ----- Original message ---------------------------------------- From: "Porritt, David" <dporritt at mail.smu.edu> To: "Pianotech List" <pianotech at ptg.org> Received: 8/21/2008 3:56:29 PM Subject: RE: more on floating pitch >I think that by compromising the piano will be marginally more stable. >I float mine at pretty close to what A4 gives me and in your case that >would be a raise in the bass and lowering in other areas, but I can live >with that. >dp >David M. Porritt, RPT >dporritt at smu.edu >-----Original Message----- >From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On >Behalf Of Mike Spalding >Sent: Thursday, August 21, 2008 3:24 PM >To: Pianotech List >Subject: Re: more on floating pitch >I guess I failed to make my point clear. I am not asking for a tutorial >on pitch raising - I feel I have a method that works well for me within >the amount of time the school is paying for. The point is, when the >humidity increased from 38% to 68%, parts of the piano barely moved, and >others moved a lot. This is the way most pianos behave (except perhaps >for a Nossamanized concert grand) Suppose I float the pitch at +8c. I'm >pitch-raising the bass up to 8c, I'm pitch lowering the tenor up to 16c, >and the treble up to 27c. Pick another float frequency, the situation >is the same. The majority of the piano gets a significant pitch >correction in order to match any chosen float pitch. Therefore, there's >no benefit to floating. Might as well target 440 every time, it won't >be any less work, or any less stable, than floating at some other >pitch. And no matter what pitch the piano gets tuned to, when the >weather shifts the piano will go out of tune with itself, whether its >drifting towards A440 or away from A440. So why not target A=440 every >time? >Mike >Jon Page wrote: >> >A0 +0, A1 +3, A2 +5, A3 +18, A4 +12, A5 +24, A6 + 35, A7 +20. >> >> If being dead on 440 is not important (studio work) I would tune this >> piano at +8c. It will be back down to 440 or lower in a few months. >> >> Unless you're desperate for work, float the pitch. one pass. >> -- >> >> >> Regards, >> >> Jon Page >and John Formsma Wrote: >I would assume the problem came when the piano was tuned to A440 in >March. This would likely be just before the RH begins to rise (at least >it does here in Mississippi around that time). If the piano had been >tuned to A439 then, it would be closer to A440 now. >I would agree that a one-pass tuning might not have every note "spot >on." However, one could get the piano in decent musical shape with a >one-pass tuning ... even with numbers that you mention below. Since this >is a school piano, and schools generally won't pay for a pitch >correction, I'd do the best I could with a single pass. >My attempt would be stabilizing the entire middle section to A440 first. > (By tuning all unisons there.) Then begin working on the treble, >tuning slightly flat octaves, and tuning unisons as you go. By >listening to your progress, it will become evident if you've chosen the >right amount of "flatness" to your octaves. My first try would be >tuning the treble so that the octave-fifth has a beat of 1-2 bps. This >would be perhaps even a slightly flat double octave. But, it usually >goes back up when it's that sharp, so you anticipate that. >If you have to correct some, you have to correct some. <G> It's not >that hard with shimming. I'd just correct the worst ones in the time >that I got paid for. >-- >JF
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