Yow-yow-yowing bass strings

[gordon stelter]

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
> 
> 
> 


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