I thought we're supoed to use F2 with the fork. Marshall ----- Original Message ----- From: "Robert Scott" <robert.scott at tunelab-world.com> To: <pianotech at ptg.org> Sent: Thursday, May 04, 2006 8:57 AM Subject: Subject: Re: Partials of Forks? > David Ilvedson wrote: > > They used an A440 fork to tune A3 (temperment starting point) > > F3 - A3 = F3 - Fork. > > > > and Mark Schecter responded: > >> Well, call me old fashioned, but this tunes the fourth partial of A3 to >> the second partial of the fork (?880), which would only yield A4=440.0by >> luck. They are introducing two variables; the distance betweenpartials 1 >> and 2 of the fork, and the distance between partials 1 and 2of A4. The >> sum of those differences, unless by chance it is 0.0, is the_offset_ of >> A4 from 440.0. At least, that's the way I figure it. > > Forks do not have partials - at least not in the same sense that piano > strings have partials. When a fork is struck and held in the hand, the > only sound coming from that fork is A-440. There is no 880 at all. So if > you play the note F3 along with an A-440 fork, you will not hear any beat > because 440 is not in the partial series for F3. However, you can hear a > beat if you do this: strike the fork and then rest the support on a > wooden surface, like we normally do to make the sound of the fork louder. > Now play F3 along with the "amplified" fork and suddenly you do hear the > beat at 880. What made the difference? It is not simply that the fork is > louder. The 880 comes from the non-linear interface to the wooden surface > which introduces harmonic distortion products. These distortion products > are true harmonics - exact multiples of the fundamental. So if you do > manage to coax some 880 out of a 440 fork using harmonic distortion, you > can be assured it is exactly 880, not ! > 880.5. > > Robert Scott > Ypsilanti, Michigan
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