<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40"> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)"> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"/>  <style>  </style>  </head> <body bgcolor=white lang=EN-US link=blue vlink=purple> <div class=Section1> Hi Ric,<o:p></o:p> <o:p> </o:p> Scott Jones and I had a rather lengthy discussion about his “string couplers” and the backscale. Not in the tuning of the backscale but in a new concept; tuning stability. He asked that I try to determine which of the trichords seemed to go out seasonally (typically the left or right string) and couple that one in the backscale to act as a “spring” of sorts and possibly aid in overall stability. The hope is that the string that seems to “go south” (my words) will not go quite as far out and the tuning will at least appear to be more stable. He’s not “selling” this idea but wants try this out. I think he may be onto something.<o:p></o:p> <o:p> </o:p> So… the reason I’m adding this to your post is that I do believe this is worth a try and will also help in “tuning” the duplex. It works wonderfully for the front and may work in the back. If you’ve never tried these they definitely have a place in pianos. My 2 bits.<o:p></o:p> <o:p> </o:p> Regards,<o:p></o:p> Jim Busby BYU<o:p></o:p> <o:p> </o:p> <div> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center tabindex=-1> </div> From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On Behalf Of Richard Brekne Sent: Tuesday, May 29, 2007 3:14 PM To: caut@ptg.org Subject: [CAUT] Tuning the back duplex<o:p></o:p> </div> <o:p> </o:p> Hi Daniel I wonder if you might share your reasoning as to why the tuning process will not allow for tension in the back length to remain higher then in the speaking length once the back length is set to a higher tension. It would seem to me that if one was careful not to move the speaking length tension overly much in tuning, that this would have no affect. Playing would tend to pull on the string... if anything tending towards more tension on the back length... tho perhaps if the tension on the back length was overly high  friction might slip and an evening out of the two segments might occur. Another thing that strikes my thinking is what about the tension on the segment of string on the bridge surface itself.  Today I was working on a 7 year old D which has early stage killer octave problems developing.  There was a good deal of phasing going on and some amount of bonified false beats (single string beating).  I virtually eliminated all of this by first pulling up the back length segment, then tuning with quite hard test blows with sustain pedal down to let loose any that I'd over pulled, followed by finding a pitch for the back lengths in which there was no false beat apparent for these lengths and tuning them as unisions to that pitch.  None of the resultant pitches for backlength unisons were consonant with the speaking lengths... so the problem you allude to with ringing after damping was not apparent. I just got back from the concert where I heard the whole thing from the studio of the National Broadcasting company here in <st1:country-region w:st="on"><st1:place w:st="on">Norway</st1:place></st1:country-region> at the concert hall in town.... not a hint of change through the whole concert. I'll see the piano again in the morning.  Interestingly enough tho... the experience did open my eyes a bit more into the world of the percussive problems of the killer octave.  Nothing like a high class studio to shed a kind of acoustic-microscope on piano sound. Cheers RicB <o:p></o:p> <blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'> > just what is the most optimal frequency relationship to the   > speaking length to tune these lengths too is another question.  I'm   > getting the feeling that if one assures that the tension is higher   > in the back length then the speaking length.... that you end up   > with a cleaner sounding instrument.... but I am still   > experimenting.  Any thoughts would be greatly appreciated > > Cheers > RicB<o:p></o:p> </blockquote> <blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'> I have not tread lightly here but delight in joining a fine mind in a   study in which many have indulged in passing as have I. I find as have you that higher tension is favorable, variable   tensions (read variable pitches) not commensurate with the series of   the speaking length are not too noticeable, but any piano with   tunable back lengths cannot stand perfectly tuned back lengths for   the resulting stridency of the ringing after damping. Again, my own experience indicates regular tuning process rarely can   keep the residual tension higher than the speaking length and that   higher tension on the back length could aid soundboard collapse. Your contributions are greatly appreciated and look forward to a   continuation of same.<o:p></o:p> </blockquote> <blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'> <o:p> </o:p> Daniel Gurnee  HSU Ret.<o:p></o:p> <o:p> </o:p> </blockquote> </div> </body> </html>