<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 flexible 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 >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 _______________________________________________ pianotech 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!