<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=iso-8859-1" = http-equiv=Content-Type> <META content="MSHTML 5.00.2614.3500" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY> <DIV>Murray,</DIV> <DIV> </DIV> <DIV>"Mr. Centre"??? You haven't taken to naming = the strings?? Pullllleeeeeeeeze!</DIV> <DIV>This is not like you. Too much sesame street = perhaps? Sorry......just noticed</DIV> <DIV>it wasn't you but an American cousin. Had me = scared though. ;~\</DIV> <DIV> </DIV> <DIV>Best,</DIV> <DIV>Bob</DIV> <DIV>----- Original Message ----- <DIV>From: Murray Seminuk <<A href="mailto:seminukm@cadvision.com">seminukm@cadvision.com</A>></DI= V> <DIV> </DIV> <DIV>Subject: Re: ETD question re: unisons</DIV></DIV> <DIV> </DIV> <DIV>> Hi Terry >Which string do you tune first after Mr. = Centre? I usually tune the left string > first and then the centre = next.> </DIV> <DIV>>Regards > Murray </DIV> <DIV>> ----- Original Message ----- > From: "Farrell" <<A href="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</A>>= > To: <<A = href="mailto:pianotech@ptg.org">pianotech@ptg.org</A>> > Sent: Thursday, February 15, 2001 5:20 AM > Subject: Re: ETD = question re: unisons > > > > Just to add to what folks = observe. I routinely observe this phenomena. I > > tune with my SAT, use = two mutes and tune my unisons as I go. I kinda like > > that because I = can easily observe my center string pitch to make sure it > is > > = stable. I tune Mr. center to the SAT, and then pull in my first unison. > = > Often in that killer octave area I see the whole thing drop a tad on = the > SAT > > (go flat) and I think, hmmmm, did my center string drop = or did this funky > > thing occur? I move my mute so that only the = center string sounds and > > Walla - right back to pitch! This happens = often. It sure seems real to me. > > And it definitely varies from = note to note. Some notes will have no > change, > > some a tiny = little bit, and some a frustrating amount. > > > > Terry Farrell > > Piano Tuning & Service > > Tampa, Florida > > <A href="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</A> = > > > > ----- Original Message ----- > > From: = "Murray Seminuk" <<A href="mailto:seminukm@cadvision.com">seminukm@cadvision.com</A>> = > > To: <<A = href="mailto:pianotech@ptg.org">pianotech@ptg.org</A>> > > Sent: Thursday, February 15, 2001 12:31 AM > > Subject: = Re: ETD question re: unisons > > > > > > > Hi Roger > > > If  you can audibly here that the note is = out of tune with the octave > > after > > > all these = attempts at tuning the unisons,then the note did not stay in > > = tune > > > period.If the full blush of the Rct acts the same as the rotating lights > > on > > > the Sat ,I think that one does = not have to look any futher.The unison > can > > > only be = tuned pure with the ear and good hammer technique.You also > > = mentioned > > > that this is a newly strung piano. I don't think that this = piano would > be > > > very stable yet to do a test like = this and produce any kind of results > to > > > make any = reliable assements.Keep on  testing. > > > Regards > > = > Murray > > > > > > ----- Original Message = ----- > > > From: "jolly roger" <<A href="mailto:baldyam@sk.sympatico.ca">baldyam@sk.sympatico.ca</A>><B= R>> > > To: <<A href="mailto:pianotech@ptg.org">pianotech@ptg.org</A>> > > = > Sent: Wednesday, February 14, 2001 9:37 PM > > > Subject: = Re: ETD question re: unisons > > > > > > > > = > > Hi Muray, > > > >           &nb= sp;    The test was done on a newly strung and hammered piano, > > = > > regulation set with very close letoff. etc.    Each = string was sampled > > 10 > > > > times on the spectrum = analyser to ensure the partials on each string > > were > > > = > close. Also verified by ear. Each string was tuned several times = for > > full > > > > blush on RCT, .01cent.  The test = was done with back and front duplex > > > scales > > > = > muted. > > > > The piano was a really nice Steinway = O.  But I have have had similar > > > > results from my = SD10. > > > > Several notes were done in this manner each showed a drop = of 0.2 - 0.3 > > > cents. > > > > And yes you can = just hear the shift when checking the octave. .3 cents > > is > = > > > very audible within the unison > > > > To do this = test all string temination points have to be in good > > = condition. > > > > Ron is slowly winning me over, re a connection to either = impedence, or > > the > > > > reverse, reactance. > = > > > Some serious study of the principals of reciprocity is badly = needed > > before > > > > we can begin to start to understand = what is going on. > > > > Traditional piano thinking has been to = look at the effect of loading > > with > > > > respect = to the impedence of the board.  Mechanical reactance (I > think = ) > > > > will be looking at the boards effect on the = strings. > > > > They are not nessesarily the same. > > > > The = subject is so complex that it would make a great PhD project. > > > = > Good to hear from you. > > > > roger > > > > > > > > > > > > At 08:26 PM 2/14/01 = -0700, you wrote: > > > > >Hi Roger > > > > = >I'm really on a roll tonight , this is my 3rd reply.Correct me if = I'm > > > wrong > > > > >,but are you saying that you tune = each string a number of times with > > the > > > > >RCT,then take a reading of the three together and have a pitch = drop > of > > .3 > > > > >cents.I have been using a = Sat for a number of year sand I find that I > > > cannot > = > > > >always use the lights to tune a unison.I do not have a RCT to = do a > real > > > > >comparison but I find that = when the lights stop there still is a > > "window > > > = '' > > > > >to tune within.With my SAT a difference of .3 cents = would be > noticable > > to > > > > >the = ear.I would wonder if all that has happened is that one of the > > > strings > > > > >is not in unison. > > > = > >Regards > > > > >Murray > > > > = >----- Original Message ----- > > > > >From: "jolly roger" = <<A href="mailto:baldyam@sk.sympatico.ca">baldyam@sk.sympatico.ca</A>><B= R>> > > > >To: <<A href="mailto:pianotech@ptg.org">pianotech@ptg.org</A>> > > = > > >Sent: Wednesday, February 14, 2001 9:27 AM > > > > >Subject: Re: ETD question re: unisons > > > > = > > > > > > > > > > >> Hi Howard, > = > > > >>          &nbsp= ;       Yes it is easy to confirm.  The test that I have > > = done > > > > >with > > > > >> a RCT show about = a 0.3 cent drop in octave 5/6. The test was > > performed > = > > by > > > > >> tuning each string individually = several times, to over come the > > > > >> interaction. = then the net 3 string unison was measured. > > > > >> The = effect is known as string coupling. > > > > >> My own theory = is that. as all strings start to increase the amount > of > > > = > >> energy into the bridge, the board is moving through a = greater > > > excussion, > > > > >> and hence dropping = the frequency a tad. > > > > >> Now I've been out to = lunch before, and I could be off base on this > > one. > > = > > >> Regards Roger > > > > >> > > > = > >> > > > > >> At 10:47 AM 2/14/01 -0500, you wrote: > > > > >> >Hi everyone, > > = > > >> > > > > > >> >Since I know nothing = about ETD's my question might be naive. > > > Nevertheless > = > > > >> >here goes: I believe that Virgil's assertion that = a 3 string > unison > > is > > > > >> >flatter than each of the single strings heard singly, is a = bit > > > > >questionable > > > > >> >or should = I say not fully accepted. Wouldn't it be easy and > > = conclusive > > > to > > > > >> >check this thesis by using = an ETD to measure this? Thanks! > > > > >> > > > = > > >> > > > > > >> >Howard S. Rosen, RPT > > > > >> >7262 Angel Falls Ct. > = > > > >> >Boynton Beach, Fl  33437 > > > > = >> > > > > > >> ><A href="mailto:hsrosen@gate.net">hsrosen@gate.net</A> > > > = > >> > > > > > >> > > > > >> > > > > > > > > > > > = > > > > > > > > > > > = > > > </DIV></BODY></HTML>