This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ---------------------- multipart/alternative attachment We have 3 "D"s here that have this "ghost" and does seem to come and go since the ringing wasn't always noticeable. My guess is that it is fairly common since 3 out of 4 of our "D"s have it. We just keep a little bit of braid on the offending duplex segment. Eric Wolfley, RPT Supervising Piano Technician College-Conservatory of Music University of Cincinnati -----Original Message----- From: James Ellis [mailto:claviers@nxs.net] Sent: Wednesday, February 02, 2005 10:09 AM To: caut@ptg.org Subject: [CAUT] "D" with a ghost Another brand new D has arrived in Knoxville, TN. Some of us in the Knoxville Chapter were checking it out at the dealer's prior to our regular meeting last night. I noticed a very prominent ghost-after-sound at note C#-6. None of the other treble notes were doing this - just the C#-6. What first called my attention to the C#-6 was its apparent short persistence, but then I noticed the ghost sound when I released the key. The ghost was persistent as well as pronounced, like a wide-open string somewhere, but no dampers were hanging up, and none were seating poorly. We even checked to see it the sound was coming from another piano (an open B that was sitting side-by-side with the D), but it was not. The whole body of the D just seemed to resonate with that sound. So, what was it? It turned out to be the rear duplex of note C-4, whose fundamental was exactly on pitch with the fundamental of note C#-6. The muting braid stopped a few unisons below that point in the scale. The remedy was obvious, but I suggested we just wait and see if anyone else notices this before anyone fixes it. There is a good chance that the ghost will come and go as the relative humidity changes and the soundboard shifts, because that section of the duplex will be very sensitive to it - more so than the speaking lengths of the strings. This is proof of what I have said so many times. The vibrations of individual speaking lengths do not couple across the bridge to their individual duplexes. They can't. Instead, the vibrations couple all up and down whole sections of the bridge, to duplexes and speaking lengths alike. Jim Ellis _______________________________________________ caut list info: https://www.moypiano.com/resources/#archives ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/5a/39/4f/d5/attachment.htm ---------------------- multipart/alternative attachment--
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