Looking back at what David asked: <<<<<<< So my question is, for example when tuning an F octave what is the distinction between 4:2, and say a 6:3 octave tuning? I have searched the archives, and reviewed my potter course manual, and still a little confused! Thanks in advance!! David West Roscoe , IL. >>>>>>>>>>> Hi David, welcome to the list. I'm wondering if you meant what is the resulting cents difference in a tuning calculated using the differing partials? If so, I just did a little experiment. I used A4,A3,A2 and A1. A4 will always have the first partial set to 0 cents, or A 440. Here is how a full upright (Thompson) matching of the octaves looks: (A4 and A3, use first partial, A2 use 2nd partial, A1 use 3rd partial... no I don't use these for tuning, I just wanted to use those for this example) A4____0 A3___-1.65 A2___-2.82 A1___-8.52 This gives a pleasing matching of the octaves and double octaves. Now, here is the same piano with strict 4:2 octaves going down from A4 A4____0 A3___-1.29 A2___-1.41 A1___-4.22 And the same piano with a strict 6:3 tuning A4____0 A3___-1.96 A2___-3.44 A1___-11.82 Here is the same experiment on a 9' Steinway D "normal" A4____0 A3___-2.09 A2___-2.05 A1___-5.33 4:2 A4____0 A3___-.60 A2___-1.07 A1___-5.94 6:3 A4____0 A3___-2.12 A2___-3.66 A1___-7.08 And just to show the unpredictability of the partials in a smaller piano, here is a Kimball spinet. Notice on all the previous examples, the lower notes are tuned in negative values to stretch the octave so it appears "beatless". Look at the values for A3-A2 on this piano! A 6:3 matching produces a narrower octave than a 4:2........ normal (if there is such a thing on these) A4____0 A3___1.21 A2___-2.01 A1___-9.88 4:2 A4____0 A3___1.21 A2___-2.26 A1___-6.49 6:3 A4____0 A3___2.22 A2___-.92 A1___-7.99 Help any? Ron Koval Chicagoland _________________________________________________________________ The new MSN 8: smart spam protection and 2 months FREE* http://join.msn.com/?page=features/junkmail
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