<html> Hi Oleg,              Since you have RCT, here's a test for you to try. Measure the offending note in the PAZ mode a look at the harmonic content, then measure the next note, the over lay will give you a comparison. I'll bet a Dollar to a bottle of Bordaux that a voicing discrepency will cause the tuning error. e.g. If you hang a new set of hammers on a Yamaha C3 calculate a tuning, High C will be about 40c sharp, voice and the upper partials dramatically increase, recalculate the tuning, and high C will only be 30c sharp. The Inharmonicity alters slightly, this I think is part of the problem. I'm currently working with a mechanical engineer who is an expert in non linear materials, initial indications is that Youngs Modulus, that is a linear equation is not quite acurate, since there are so many variables we are trying to dream up some experiments to prove or disprove this theory. Depending on the piano, if the string under tension is on the downward side of curve of elastic limits, then the problems are more noticable. I also think the age of the wire comes into play since the factor of creep enters the picture. Since creep is effected by time the subject becomes more complex. Again I have measured old wire and compared it with new, the change in harmonic structure is quite dramatic.( to the better).     If you want to experiment with PAZ and tuning/voicing you will find some amazing results, it seems to me to raise many more questions than answers, but may be this post will stimulate some discussions. Regards Roger At 02:17 PM 15/11/98 +0100, you wrote: <blockquote type=cite cite>Hello everyone, When i was looking for information on tuning perception, I've found this study on the tuning of trichords in the piano. I send it to your interest, as I remeber a thread about it. I once had tried to analyse the fresh tuning of a grand D S&S by one of our best tuners here in Paris, and I've found that on any triplet checked (with RCT), 2 of the cords were in tune with no more than 0.1 or 0.15 cts diff at the 2nd or 4th partial level, BUT a 3rd corde was "out" by 0.25 to 0.8 cts, not always the same cord but always one. When hearing the tuner at work I clearly have the feeling he plays to the 2nd or 4th partial resonnance when tuning unissons (no strip miuting by there). It was in a large concert hall with a good soun return. I feel the tuner use the partial modulation to obtain a "projection " of the sond in the place. I may admit I have tried to do that and have found difficult to 3HEAR" the sond in front of the piano as if I where 5 meters farther. I will assit on a cooloque on the perception of the tuning of the pianos in a fe you. By the way Del, ther will be something on the pros and cons about old or new wood for the resatauration of ancient pianos. Will forward it too if avaible. Following is the file (english version) Best regards to all of you . Isaac OLEG Tuner/ technician. Paris - France Serveur © IRCAM - CENTRE GEORGES-POMPIDOU 1996, 1997, 1998. Tous droits réservés pour tous pays. All rights reserved. <div align="center"> <h1>Tuning of Trichords in the Piano</h1> </h1></div> Eric Marandas, René Caussé (IRCAM), Vincent Gibiat (LOA/ESPCI, UP7 URA CNRS) ISMA 95, Dourdan 1995 <hr> (<a href="index.htm">Version Française</a>) <h3>Abstract</h3> Are the two or three strings struck by the same hammer in a piano tuned in perfect unison ? We used an experimental procedure for precise frequency measurements of a single vibrating string (the others being damped), using zero-crossings of the sound pressure signal (filtering out all but the fundamental). We determined the "mistuning" between the three strings of unison groups, from F1 to C5. The average "mistuning" was approximately 0.5 cents. This value is three times lower than the frequency resolution of the ear given by works on psychoacoustics. <div align="center"> La version électronique de ce texte n'est disponible dans son intégralité qu'à partir des postes de consultation de l'Ircam, pour des raisons de copyright. Les rapports de recherche et les revues musicales de l'Ircam (ainsi que des disques, des brochures d'information...) peuvent être commandés auprès du <a href="mailto:comm@ircam.fr">service de Communication</a> de l'Ircam (tél: 01 44 78 48 98). The full online version of this text is available only from within IRCAM, for copyright reasons. The Technical Reports, all the IRCAM periodicals as well as other publications (recordings, brochures, etc.) can be ordered from the IRCAM <a href="mailto:comm@ircam.fr">PR services</a> (phone: +33 (0) 1 44 78 48 98). </div> ____________________________ <a href="/index-e.htm">Server</a> © IRCAM-CGP, 1996, 1997, 1998 - file updated on 10/14/1998 at 18h13m12s. To write: <a href="/messages/mail.htm">MESSAGE</a> </blockquote> <div>Roger Jolly</div> <div>Baldwin Yamaha Piano Centre</div> <div>Saskatoon and Regina</div> <div>Saskatchewan, Canada.</div> <div>306-665-0213</div> Fax 652-0505 </html>