Sounds to me like the sympathetic vibration of a poorly damped string higher up in the scale. Play "yowing" notes and press gently on dampers to see if stops. Thump --- Carl Meyer <cmpiano@attbi.com> wrote: > > ----- Original Message ----- > From: BobDavis88@aol.com > To: pianotech@ptg.org > Sent: Monday, January 20, 2003 2:20 PM > Subject: Yow-yow-yowing bass strings > > > Friends, > > Hep! Hep! (Okay, I grew up in Texas) > > I don't think I can hep you but I have comments > and questions. > > I'm not sure I know what the sound is. Would you > classify it as a false beat? What rate is it? Is it > the same rate for all bad notes? Did you try tuning > it 25 cents sharp and then 25 cents flat to see any > change? A longitudinal vibration will not change > frequency with tuning. > > There is a device I've long wanted to build. It > would be a mike fed to a preamp and a tunable filter > connected to a tight fitting fluid filled head > phone. This would allow you to listen for and tune > (with the filter) in the offending sound to identify > frequency and possibly identify the source. There > are many uses for this and I now have even more > reasons to build it. Other than that I don't have a > clue. > > Carl Meyer Assoc. PTG > Santa Clara, California > cmpiano@attbi.com > > > I need an accurate scientific explanation for why > SOME single bass strings go yow-yow-yow, when played > by themselves. > > A new customer I am about to go see, with a new > Steinway B, said he wanted me to maybe replace some > bass strings that were "wobbling." I thought, okay, > unisons or voicing, but then he said they were > singles. I realized I had accepted that sound for > decades, and just tuned around it, considering it a > shortcoming of shorter scales. Later that day, I > listened to 5 B's, 4 L's, and a D, as well as a 7'4" > Boesendorfer. > > All the Steinways had yowing singles, but not > necessarily on the same notes. Some notes would be > clear. The D was the best of the Steinways, > reasonably clear, and the Bösendorfer was extremely > clean. > > The Steinways are single-wrapped and the Bös is > double-wrapped, but I also listened to some 126 cm > Bostons, which are double-wrapped, and they had > random wows too. > > I've always chalked it up to "inharmonicity" or > longitudinal waves or something like that, but I > realized that doesn't really work, and now it's > driving me crazy not to be able accurately to > explain this. What is happening, and why is the > Bösendorfer so clean? > > Wobbling in Stockton CA, > Bob Davis > > > __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
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