Hi Michael, To make sure we are on the same page a0 is the bottom note of the piano c1 is the first C and a4 is tuned to 440. First inharmonicity is not my theory. There is a great explanation here: http://www.afn.org/~afn49304/youngnew.htm Second inharmonicity may cause the type of octave that you are describing (called a 2:1) to be wide by 1 to 8 cents depending on the scale design of the piano. Third most tuners would do a 4:2 or a "wide" 4:2 or a 6:3 in the middle of a piano, resulting in an even wider octave at 2:1. Fourth coupling to the soundboard may cause the total inharmonicity in the system to be a negative number resulting a 2:1 octave that is smaller than your "pure" 2:1. (i.e. narrow by 1 or 2 cents) Fifth Reyburn Cyber Tuner calculates a 6:3 from f3 to f4 that is 3.27 cents wide for a Yamaha C3. I don't have the piano in front of me so I can't check the 4:2 and 2:1 values at the moment. Sixth it would not be uncommon for a0 to a1 in a large concert grand to be tuned as a 12:6 octave. The 2:1 may not even be measureable in such a situation as it is a very tiny fraction of the total sound output, but if it does exist would be extremely wide. One reason I asked what sort of ETD you were using was to know whether it had a needle type gauge. You answered that it did--without giving the make. Needle type gauges suffer from parallax error when a user attempts to "read" them. Some are not very well suited to the task of tuning a piano. See this web site about parallax error. http://www.usna.edu/EE/ee331/MAn1.PDF look on page 13. At 11:05 PM 12/11/2003 -0000, you wrote: >Hello Don >Please prove your inharmonicity theory when plotted against that "small >equation". A pure 8ve. is surely that where the higher note is exactly >double that of the lower one.....Or is it? >Over to you with...:-) >Regards >Michael G (UK) Regards, Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T. mailto:pianotuna@accesscomm.ca http://us.geocities.com/drpt1948/ 3004 Grant Rd. REGINA, SK S4S 5G7 306-352-3620 or 1-888-29t-uner
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