You know, I would go back and tune the piano with the SAT Master tuning page you have in memory and take another listen with the original or new Master tuning committee. If a problem really exists, often a few tweaks can make it right and the tuning re-recorded. I apologize if this has already been discussed! David ----- Original Message ----- From: "Fred Sturm" <fssturm@unm.edu> To: <caut@ptg.org> Sent: Monday, January 14, 2002 10:36 AM Subject: Re: CTE-Master Tuning > Avery Todd wrote: > > > > Fred, > > > > I think what people are talking about is that with humidity changes, the > > piano can change, thereby affecting the FAC numbers, thereby affecting > > the "Master Tuning", in this case. This has been being talked about > > lately on the pianotech list about the climate changes changing the FAC > > numbers somewhat. > > > Avery, > One of the basic features of the FAC is the choice of partial it tunes > by. Dr. Al found that by tuning the 4th partial, thirds would progress > nicely (because the third is produced by beating between 4th partial of > the upper note and 5th partial of the lower). So all that is needed is > for the numbers to progress evenly to get smooth thirds. Hence, even if > the "A Number" shifts, the thirds will still progress well. All that > will be affected is the width of octaves, and the pitch of A4. (It's a > bit complicated, but this is basically true). > The only place this doesn't work is over bad inharmonic breaks, where > inharmonicity jumps. But test pianos shouldn't have such bad breaks. For > these reasons, I am very skeptical that humidity would cause a piano to > change in such a way that thirds tuned to the same numbers wouldn't > progress the same. (The tuning test uses different - lower - partials > than the FAC program, but still, I find it hard to believe that humidity > change would have such an affect. Unless conceivably the bad > progressions happen over an octave break, particularly B2 to C3, > possibly B3 to C4 and B4 to C5.) > > Joe Goss wrote: > >Hi Fred, > It is possible to change the SATll program numbers of a FAC tuning and > not > know that they have been changed. Only a hard copy will verify the > correct > numbers. > I know this to be a fact because a few years back when I was using the > canned tuning programs and using the offset to a different pitch, > several of > the programs that were being used a lot suddenly were not giving a smoth > progression and had to be reprogramed. > > Joe, > Well, I don't know precisely how the SAT's interiors work, but I > believe that numbers inputted into memory stay the same. That is, > individual cents numbers entered to memory for individual notes on > individual pages of memory. (They'd better, or I want my money back ;-) > ) > Test tunings have nothing to do with the FAC program. THe notes are > simply read, and then entered one by one into memory on a particular > page that is there for the purpose. So there shouldn't be any > calculation by the machine (other than creating the associated pages, > like Detuning. But that's just simple arithmatic based on the original > input numbers, applying them to a separate page of memory). > Unless someone actually goes to the page on which the master tuning is > recorded and changes individual notes, I don't think there is any way > they can get changed. I don't think you could even enter an FAC into > that page of memory - it's pre-programmed to accept only individual > entries at particular octaves. Trying to be fool-proof. > Regards, > Fred Sturm > University of New Mexico
This PTG archive page provided courtesy of Moy Piano Service, LLC