<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=us-ascii"> <META content="MSHTML 6.00.2900.2180" name=GENERATOR></HEAD> <BODY> <DIV>This is the third-tenth test. For example, F3-A3 and F3-A4. The fifth partial = of F3 beats at x/second with the second partial of A4. Then you make the fifth = partial of F3 beat at exactly the same x/second with the fourth partial of A3. = Voila, a perfect 4:2. </DIV> <BLOCKQUOTE> <DIV class=OutlookMessageHeader dir=ltr align=left>-----Original Message----- From: = pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]On Behalf Of Matthew Todd Sent: Wednesday, September 22, 2004 9:54 = AM To: Pianotech Subject: Re: Octave Tuning </DIV> <DIV>Now, how exactly do you tune the fourth partial of the lower = octave note to the second partial of the upper octave note?  I have heard = that some techs just tune the octave 1/2 a beat wide, and leave it at = that.</DIV> <DIV> </DIV> <DIV>Now you can call me stupid</DIV> <DIV> </DIV> <DIV>Matthew Don <pianotuna@accesscomm.ca> wrote:</DIV> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px = solid">Hi Mathew, Current thought is that a unison is the only "pure" = item in tuning. An Octave can only be "beat free" at one partial at a = time. Do an archive search for octaves and you will get loads of hits. narrowest possible octave 2:1; a3 to a4 beatless at = a4 wider 4:2; a3 to a4 beatless at a5 wider 6:3; a3 to a4 beatless at = e6 It is common to tune a3 to a4 somewhere between 4:2 and 6:3--just to make the task a little more difficult. I believe this is what = Virgil Smith does when he attempts to tune the "whole sound" of the = octave. I.E. his 4:2 beats at a rate which may "cancel" the beat of the 6:3. = How long such a "balance" will last is dependant on nothing in the = enviroment changing, including barometric pressure. More on unisons: We also have to deal with the "coupled" motion of = piano strings. The bridge is a f! lexible termination. Some studies = have suggested that a one hertz difference in two strings will result = in zero beating heard. One hertz at A4 is approximately 4 cents--a huge = number for a unison to be "out". There is also some suggestion that a = truely "pure" unison gives the piano a rather "dead" sound with poor sustain. Inharmonicity: There is no doubt that the = impedance mismatch between the strings, bridge and soundboard produces a measureable effect on the width of octaves. In some cases this = "para inharmoncity" can be a negative number. Translation--the = narrowest octave would be smaller than a "theorectical" 2:1. Setting Temperament: I'd suggest you use one of the "self correcting" = temperments such as the Baldassin-Sanderson. Have a look here: http://www.accu-tuner.com/SATIIImanual/apf.html = At 07:42 PM 21/09/2004 -0700, you wrote: > need some help from = all of you. Is it true that the two things that &g! t;remain pure in = a piano when we tune is unisons and octaves? And if we do >that, the = octave will have a slight beat to it, right? I think I = missed >something. You guys are great! Thanks!! >Matthew >__________________________________________________ >Do = You Yahoo!? >Tired of spam? Yahoo! Mail has the best spam = protection around >http://mail.yahoo.com 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 _______________________________________________ pian= otech list info: = https://www.moypiano.com/resources/#archives </BLOCKQUOTE> <HR SIZE=1> Do you Yahoo!? <A href="http://vote.yahoo.com">vote.yahoo.com</A> = - Register online to vote today!</BLOCKQUOTE></BODY></HTML>